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How do I unlock an Optimus T? Is there a "vanilla" firmware I can use?
I'm an experienced iOS developer, and I just bought my first Android phone, used, on eBay. The phone is carrier locked and I'm looking to swap in my iPhone SIM card. (I have an adapter.)
The phone is carrier locked. Is there a way to root or erase the firmware to unlock it, or must I use an unlock code? If so, what are my options for obtaining said code?

Unfortunately it appears your only option is an unlock code, I've just done a search.  This XDA thread has a couple ways to get into the unlock screen so you can enter the code.
Your options for get the unlock code are to ask the carrier the phone is locked to -- they might give it to you if they're feeling nice -- or to buy it online.  There are no reputable sellers of unlock codes online, of course, but you could search around and find someone whose experience seems reliable and use the same service that they did.

I have this phone, and I have T-Mobile.  I called *611 and told them I was going to be traveling in Europe and needed a SIM unlock code.  They agreed and it arrived about 12 hours later.

You can use unlock code to unlock your LG Optimus T which is the safe and easy way. You can get the unlock code from the service/network provider. But,Mostly they will provide the unlock code if your phone if off contract . In that case you can get the unlock code from online vendors like MobileUnlockSolutions.com for a price .They will give you the unlock code along with instruction on how to unlock.

Simple solution for you. Get your LG Optimus unlocked by obtaining an unlock code so that you will be able to swap in your iPhone SIM card. Just google for cheap LG SIM/Network Unlock codes. Be careful about sites that betrays you. You can also find some code vendors on ebay too.


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Voice Actions to Start Applications?
I looked at the list of Voice Actions on Google's website and couldn't find one for starting an application of my choice.
Is starting applications supported by Voice Actions?
If not, can a user add this feature via some setting or by an app from the market?

The built-in Google Voice Commands can't (at this time) launch apps.
However, a quick search on the Market revealed a few possible alternatives. Here are two:

Cyberon Voice Commander
Voice Actions

Thanks. Of the two applications you posted, only Cyberon advertises being able to "Launch program". I'll check that out.

It depends on your application. For example, the "Listen to ..." ties in with several music apps like Spotify and mSpot. So far there's no way to launch an arbitrary app through voice actions if the app doesn't support one of the voice action keywords.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


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What's this icon that looks like 3 vertical waves in the status bar of my Droid X?
There's this vertical river-looking icon thing in my status bar? Nothing's claiming it in the notification window.
Crude recreation:

Complete Android Guide has nothing. I suspect it's a particular app.

The third table in this page mentions "Vibrate":
https://motorola-global-portal.custhelp.com/app/answers/detail/a_id/48504/~/droid-x---phone-status-%26-notifications
Even though the first table clearly depicts a different icon for the vibration mode, although with the same zigzag pattern.
The pattern is also the same as the icon I have for vibration mode on my SGS:

Cheers!

Yup, the update (2.3) for the Droid X made the icon even more abstract and didn't include a phone thing.

Looks like the icon for the "Silent" or "Vibrate" mode.  These icons are different depending on the skin manufacturers/carriers put on their phone, but those wavy lines usually represent vibration.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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Android Software or Device to present Application on Screen
Well this is something that came to my mind, Does anyone know if there is a Device or a cable that i can plug to a DataShow so it is possible to present an Android Application live and fullscreen, doing all the tap and swipe events?
If not at least is there is something that its able to record a Screencast of an android application for presentation purpose  of course?
PD. BTW i did not found right tag for this question, so if someone can retag it it would be nice too :D

See this for screencasting live and this for recording the device screen using the device.  It's probably better to capture live and record at the PC I would think, to get a better framerate.

I happened to found that the best way to do this is with a project call androidscreenscast, which is really easy and great:

just plug your phone.
Downloads the jnl on the site
And enjoy your screen

I wrote a post about my experience Present your android application on a Datashow.

You might be able to connect an Android phone via the 3.5 mm headphone jack (using TV out), with a RCA cable if the project supports it, or some variation, of course.
Also, I think there are now tablets which have a HDMI output port (or some variation) which you can connect to a datashow (eventually with a VGA adapter).
When connected, what is projected is exactly what you see on your device.

can you point me out this 3.5 mm headphone jack solution looks interesting have you try it successfully yourself?

yes I did, it is very easy actually... look at this video: http://www.youtube.com/watch?v=iiwT06dg0HU

:O it display the video as an output... nice i think i'll stay with the software solution


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How to enable non-3G data
After I got my mighty Fly-Ying FG8 I didn't care for mobile data, mostly due to the measly 5MB data plan with extortionate overage charges. I miss the occasional emails on the road, Waze navigation and A-GPS so I thought to put these 5MB to good use.
The problem is that in the Settings => Mobile networkד I have only "data roaming", "Access Point Names" and "Network Operators" on both SIMs. I couldn't make the device use its EDGE capability. Does anyone know how to turn it on?

I'm confused. Do you have a non-3G data plan? If not why wouldn't you want to use the fster 3G?  Modern phones/networks only default to EDGE when there is no 3G connection.  It's not managed separately.

The phone doesn't support 3G. It's true, the question and the answer were "how to enable data" rather than "how to enable EDGE"

Ah, OK. Glad you figured it out :)

Appereantly, you have to define an "Access Point Name" in order for your mobile data to work.
in Settings => Wireless & networks => Mobile networks => Access Point Names => menu => New APN
The settings vary by operator, you can find the Israeli ones here.


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What is SNS App?
I'm using a Samsung Galaxy I551 with Android 2.2 FroYo.
Sorry for my ignorance, but I have not idea what is that app (which came installed and without rooting can't be removed). And it is using 15MB of my internal storage! I only have 160MB so that is a lot.
What is this app for? What will happen if I clear its data? Are those 15MB included in the storage DiskUsage categorize as "System Data"?

Social Networking Service.  I believe it's used for social networking widgets.  Clearing the data will just clear the posts and account info in the widgets.  I'm not sure if the Facebook or other apps rely on it.

So, nothing bad should happen if I delete its data? It acts like a cache?

@Diego Yep it should be fine.

Nothing seem to went wrong.. Not even with Facebook widget! Thank you!!

I was able to force close the app from the Settings -> Application menu (but I had to do it 4+ times for it to stay gone, and I also tried a task killer on it before that but it came right back.)
Force close has kept it off for twenty minutes now! :) I hope it stays gone. I don't want to have to root yet.

Just to enhance Matthew's answer:
An "SNS" contact can also come from SKYPE if the app is installed.
I used to "Skype out" to my Dr. so skype knew his number. When I look up his name on my Samsung stratosphere phone, it is not found. However, I go elsewhere, get his number, and put it in, it pops up his name!  Frustrating!
Today I solved it: he can't be looked up as a "contact" but is in my FAVORITES (!! Favorites but not contacts ?? !!)  and when I "edit" (from putting his number and having the name come up) then it says "can't edit SNS data", which is how I got to THIS message thread. So yes, probably twitter, facebook, etc, but for sure "Skype" too!

I think it is Simple Notification Service
Thus for platforms that use push notifications (Skype, Google+, Facebook, Twitter, etc) you will see this application updated from time to time.
Admittedly as a Network Security Professional, this made me pause when I saw it updated as my S4 is rooted, but turns out it is a normal item.

Simple Network Service~
Wouldn't recommend uninstalling. Sometimes apps we think are garbage turn out have some dependencies from other apps. Boo boos involving deleting system apps can be hard to fix unless you make a backup in your custom recovery. BUT If you are curious or paranoid about what an unrecognized app says or does and to whom, behind your back... I recommend looking into an amazing app called Donkey Guard. Say for example FB wants to use your GPS to secretly locate you. Donkey Guard halts the app, Alerts you to what it wants to do. Then asks if you want to deny, allow function to app or submit your own fake info. Mine set up to give FB fake GPS coordinates that put me located at the Playboy Mansion. Or keep anything from being able to tell if your net is from data or wifi. It even stops apps from knowing anything about your data service including ISP provider and stop from using cell towers from location triangulation. Also works for location cheating/spoofing on games like Ingress or Pokemon, without having to hack and get banned.


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How can I find why I'm using so much data on mobile network?
According to my provider, I've used 6.8MB of data within 3 days.
The thing is, I don't know how. I've installed DroidWall and WiSync and only used Waze (a navigation app). I installed Traffic Monitor which shows Waze using less than 800KB and other apps even less (some of them used traffic before I setup DroidWall)
Any clues as to what is using 6MB??

It would make sense for a navigation app to use more than 800 KB. I would suspect Traffic Monitor is inaccurate, personally.

Why should it use so much? I predownload all maps. It syncs traffic data, that's it. And I've used it for a total of maybe 2 hours.

pre-downloading the maps is going to use data. And even if you predownload the maps, it will still use the network to check if your route needs changing. Plus there are other apps that will check and sync information. if you want to ensure that you dont use any data when using the navigation, you can try to disable the data network.

preloading over wifi... checking if route needs changing should not take 800000 bytes. something is definitely using data, the question is how to find it.

Try My Data Manager.  It says it can report usage per application.

My Data Manager is a free app available in the android market which will aid you in catering your needs. It will give you a detailed statistics of which app/service used how much data.
Edit : did not notice this was answered in the comments already.


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Is There *Any* Way To Increase Internal Memory?
Ok, even to me this question sounds stupid but I let's just go with "the only dumb question is the one not asked".
I have nearly 14Gb free on my SD card but the Motorola Droid only has 128Mb internal so I am constantly fighting "low memory" warnings.  I have moved every app that I can to my SD card.  This is not only a hassle, for some apps (*cough*AnythingGoogle*cough*) I have to choose to either have Widget functionality or sacrifice my precious internal space.
Question: Is it physically possible for me to upgrade this internal memory?
Although I believe answering that question will cure my woes, I will open it further to ask: Do you have a recommendation on what I could do differently (other than just delete your crap!).  As I said, I have plenty of (SD) space so I find it asinine to have to make sacrifices because of these short-sights in this phone's design (after all, who would ever have an app larger than 1k, right?  You'll never come close to using 128Mb...).

Theoretically, of course, you could modify your hardware.  But this is not remotely feasible for 99% of us.
One thing you can do -- if you root -- is to install various apps that will allow you to move more to the SD card.  You could also try a custom ROM that is smaller than the stock ROM.  If rooted you will also be able to uninstall crapware system apps (be careful not to touch the important onces).

I actually removed my crapware (the only reason I root in the first place).  I did find an app to move any application to the SD card, but some of the larger ones (like Google Maps) I'm stuck leaving on internal or I'll lose widget capability.  Is there a way around this?  I know it was implemented for security reasons but I'm running out of options.  Even still it looks like most of my internal space isn't taken up by apps, but stuff like contacts, etc.  I'll have to dig a little deeper to see exactly how it pans out.

@Fantabulum I believe you can do some fancy partitioning/mounting/aliasing to make Android think that the SD card is internal storage instead of external, but that's risky and I can't find where I read how to do it.  As well it would cause a lot of apps to stop working anyways -- Android initializes services before the SD card is mounted, so apps with services would break.  You could try this in a terminal app on your phone: su then pm setInstallLocation 2. That will set the default install location to external storage, and may let you move a few more apps.

There are ways to get all of your installed apps to the SD Card, but often they include the need to run a 3rd-party custom firmware, and having to re-partition your SD Card.  Take a look at S2E (https://market.android.com/details?id=ru.krikun.s2e ) and DarkTremor (http://forum.xda-developers.com/showthread.php?t=715940 )

@Gary Link2sd will help you move more to sd card at the same time preserves any "widget" functionality. It is the app that you are looking for!


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How To Stop Rejecting Messages At Low Memory?

Possible Duplicate:
I can't receive SMS when I have low storage

When my phone reaches ~22Mb (internal) free space, my phone starts to automatically reject text messages.  Assuming they're on internal storage, can the storage location somehow be changed to external storage?

I wonder if a third-party SMS app might help -- but installing one wouldn't help with your limited storage problem.  This question has the location of the database, and this question covers trying to disable the "feature".  I'm going to edit your question to just be about moving the storage location, if that's OK.

@Matthew: Thanks again for your help.  I'll see if I can muster up such an app.

Are you sure that it's because the phone is low on free space, or could it be related to this question?

I actually went through and deleted all of my messages.  Since that didn't clear up much space, the problem persisted.  I appreciate the link though.

This is a known and reported bug from 2009. ( See the answer to my question )
Google says they fixed it in Android 2.3.

Currently, as far as my knowledge goes there does not exist an SMS app which automatically receives it and stores it on SD card, but there does exist a SMS backup feature which creates a backup of the inbox onto the SD card.
You'll have to uninstall some apps to free up space to receive more messages. Not much else you can do about this.

Thanks for the tip CustomiZer.  I just can't believe that with over 20Mb (~20% free) I cannot receive a message that's a few Kb in size.  I can see why there's this check, but it definitely should be customizable.  Really, the only thing I have installed on the internal is updates to build in apps (Google Maps, etc).  Maybe I'll just to solder in a new memory chip, it'll give me an excuse to buy a new phone :-)

If you wonder about the 20 MB See http://code.google.com/p/android/issues/detail?id=4991#c145 (Android keeps as much free space as the biggest App you installed takes up so that you can still update it. So if you've got Opera installed (which is quite big with 22MB or something?), you need to have more than those some 22MB of free space left.)


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How to preview all UI elements/widgets and dialogs
I need to view all the different UI elements and dialogs on a device. This would be helpful while developing new platform level themes.
Is there an existing app that will do this? Are there other ways to view all the UI elements (e.g. android.widget.Button, android.widget.CheckBox, etc).

We prefer questions that ask "how do I do X" rather than "is there an app that does X". That is, we prefer problems to solve rather than helping people "shop" for an app. While the solution may very well be an app, it's too limiting to make that a starting position and skirts far too closely to "shopping recommendations are off-topic".

@Al, updated the question wording.

You should take a look at the Android API Samples.
The APIDemos application is exactly what you are looking for:
http://developer.android.com/resources/samples/ApiDemos/index.html

Thanks. This gets very close. Dialogs are covered pretty well and found most of the widgets under App/Activity/Animation (click on fade in or zoom in).


text:
Send Audio to Two A2DP Bluetooth Devices Simultaneously
I was pleasantly surprised to see that I can pair & connect my Nexus One with two identical NoiseHush N550 Bluethooth headsets simultaneously.
Unfortunately however, only one of them (always the last to be connected) seems to receive actual audio.
Is this a known limitation in the Android OS (version 2.2.1)? Or is there a setting or workaround that allows sending audio to both devices simultaneously?

Is it possible with any Bluetooth device to stream audio to two devices?

possible duplicate of Is it possible to be connected to two different bluetooth devices at the same time?

I don't think it's an exact dupe: the other question wants music audio to one and phone audio to another a2dp device. This wants both working at the same time (like a Y-cable) seemingly.

@Izzy Not a possible duplicate. The other question only mentions connecting to multiple devices but not sending output to them all simultaneously . This one is about sending to all connected bluetooth devices at the same time.

Good find, @Rexford – didn't notice that back then. So this one is rather asking for a "broadcaster". // Still: the question here is almost 4 years old. Would be interesting whether the OP found a solution meanwhile and simply forgot to answer his/her own question :)

Update, 2017 Bluetooth 5.0
In summary, Bluetooth 5.0 comes with a lot of bandwidth, which allows the streaming to two speakers at the same time.
Speaking about the 5.0 Bluetooth in the Samsung S8, AndroidPolice writes:

That extra bandwidth is required for the Galaxy S8's "Dual audio" feature. This allows the phone to stream audio to two Bluetooth headsets or speakers at the same time. You can also adjust the volume for each device independently. It's like sharing an earbud with your friend, except with fewer wires and less bacteria.

I think the bandwidth allows for sharing to two speakers at the time. I am yet to find out if any extra speakers could be added.
But there you have it. Bluetooth now evolved to support bigger bandwidth to support multi-streaming, Natively.
Any thanks? Give to the Bluetooth gods!

Old Answer:
Because this resource isn't as old as the current question is, I am sure it is the answer.
The limitation for sending output to multiple connected bluetooth devices is not about a feature. Its about how Bluetooth enabled communicate with each other.
Bluetooth, from day one, was designed for a one-on-one communication over short distances for short periods of times i.e sending an image, short video clip etc.
The use of Bluetooth has evolved and as such support for multicasting is much wanted.
Quoting from this XDA forum post:

The reason why bluetooth doesn't support Multicast is because it doesn't have the bandwith to support High Quality streaming simultaneously no would the chips really having the processing power but that could be fixed, but the main limitation is the lack of available bandwith specified in the 802.11 standard for bluetooth.

... it is clear there's a limitation, and hopefully work is done in that regard to allow support.

It seems like even in 2022 it's only possible with the Samsung S8 and a few other Samsung devices - why is that?


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Gmail app: how can I change the sender address?
I'm using Gmail for all mail related stuff, but the main address I use is not my "real" Gmail address, but something like myname@mydomain.com.
I have set up that adress as a sender in Gmail, so every mail that I send from the Gmail web app looks like it's coming from myname@mydomain.com (instead of myname@gmail.com).
So my question is:
Is it possible to use this sender adress in the Gmail Android app as well?
All mails sent by the Gmail app are sent from myname@gmail.com by default and I can't find anything in the settings to change that to my alternate address.
(as I said, it's already set up and working in the web app...the Android app just needs to access this information somehow...)
My phone is a HTC Wildfire with Android 2.2, and version 2.3 of the Gmail app, if that matters.
Thanks in advance!

I can tell you absolutely that it can be done; I'm doing it. Do you have both accounts on your phone?

No I don't, because it's actually only one account, not two. myname@mydomain.com is just set up as an alternate sender adress in my one and only Gmail account, see the link in my question.

Latest version of GMail is 2.3.5. You probably want to upgrade.

I want, but I can't. When I access Android Market from my phone, I can't find Gmail at all. From my computer, I can find the Gmail app, but when I try to install it, it says that it's not available for my country (I'm in Germany).

When composing the "From" is a dropdown menu.  It has all the accounts you've added via the webmail interface, and it's had this feature for a long time (you shouldn't need to upgrade).

Do I have to enable this somehow? When I'm composing, the "From" is not a dropdown menu, it just displays my main Gmail address and that's it. No possibility to change it.

Could it be possible that this is only available in certain countries? I'm in Germany, and I can't upgrade the Gmail app to 2.3.5 either (see my comment under the question)

I'm afraid it might be. I searched high-and-low for a configuration setting that might control this and came up empty.

That's unfortunate :(

Finally (after ove a year), the problem has solved itself. My Gmail app was upgraded to 2.3.6 a few days ago, and now I'm seeing the "From" dropdown menu as well!

@ChristianSpecht Very strange, but I'm glad!

It didn't show for me too, but after ditching my cache and data it showed up :-)


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No 3G on a Samsung GT i5800
I recently bought a Samsung GT i5800, ok. It has Android 2.1 update1 installed. ok.
If i need to connect to the internet through wifi, then i can, ok!
If i need to connect through a vodafone mobile internet connection, then i just can't!! What could the problem be? I tried to reset the phone to factory settings, and then power off, power on, then enter PIN, then? it should work, no? Why does it say's "the page cannot be displayed"? why isn't working?:O
Are there any tips? Can i provide you guys with more info? [what info?]
this is getting urgent, and i spent all the dawn with this problem.
There is an icon at the top displaying that it has enough signal strenght, but it doesn't displays an icon @the top that says it's connected through 2g, or 3g.
:( please help!

Check that the following setting is ticked:
Settings->Wireless & networks->Mobile networks->Data enabled
Also verify that the access point name settings are correct and the correct access point is chosen. You should be able to find the details of what it should be on the Vodafone website. The settings are at:
Settings->Wireless & networks->Mobile networks->Access Point Names

THANKS!!! the APN was missing, it didn't create it automatically, I had to do it manually! Thank you!

@LanceBaynes Kindly keep the profanity and caps to a minimum :P


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How to visit the /data folder on my Android on my PC?
For example

/data/data/com.android.providers.contacts/databases/contacts.db

I cannot see it both in Windows 7 and Ubuntu 11.04.

You can't directly mount the internal storage.  You need to be rooted to view it on your phone, or you can use adb pull from the Android SDK Tools to copy it off the device.

What if the phone is encrypted?

@Dante No idea. I would expect adb to be intelligent enough to ask for a password or something. I've never heard anything about encryption in Gingerbread beyond the fact that it exists.


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How to remove Samsung native email app from Galaxy S2?
I only use the Gmail app. It's annoying to have the email icon always popping aside from the Gmail icon in every contact of my phone when I only use Gmail.
Is there a way to uninstall or wipe the Samsung email app/client from Galaxy S2? I just can't find a way to take it off my phone.

Other possible duplicates: How can I uninstall built in apps?, How can I uninstall applications that are locked by phone vendor? Probably a few others.

Note that the Email app might be a required system app, and removing it could make the OS unstable.  I don't see how a tiny icon you don't have to even look at is annoying, personally.

No, you can remove Email. It might break other Google applications, but the phone still works.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How to create a shortcut to a text file
I have a text file somewhere on the SD card.
How can I create a shortcut to this file on the "desktop" to open it immediately?
(HTC Wildfire)

Amaze file manager, offers this option as well, just long click on a file or folder you would like to be able to enter to with a shortcut from the home screen and tap the 3 dots menu button at the top, then choose add shortcut.
Amaze File Manager is a FOSS file manager and it has many nice features stock file managers don't offer. For example, you can open with it files as text/image/video/audio/database with the application of your choice no matter what the file extension is - that's very useful for users who create or download/sync text files with no file extension or non relevant file extension like .log, .yaml, .json etc.

Here is another app: Shortcut Maker.
It works with the latest version of Android.
After installing the app, go to Widgets by long-tapping the home screen and click on shortcut maker. Then add the required file/folder.

You have posted five answers in toto. They are all recommending this particular app. What exactly is your affiliation with this app? Our site's policy requires full disclosure of affiliation with the product within every post the product is mentioned.

I have no affiliation with this product. The other solutions didn't work in the latest version of Android and I just got a little excited on finding the app.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How to allow Android Market License Check through a secured network?
We have a secure network that doesn't allow internet access. Unfortunately one app from the Android Market we purchased for our honeycomb tablets uses Market License Check to verify that we've purchased the app on, what it seems like, a daily basis. What site(s) do we have need to allow access to for this authentication to happen?

Unfortunately I can't find any info on this.  If you don't get a definite answer I would try allowing android.com and subdomains.

That might be tricky as we want to block users from using the android market.

This could help with blocking it on devices.  Assuming the licence server is part of market.android.com, you'd need the specific ports used as well.  This could be used to sniff the traffic and determine the info you need.

BTW, the first link only applies to paid Google Apps accounts not locking down a tablet.

The answer is "android.clients.google.com" with port 5228 (TCP).

Awesome! How'd you find it?

tablet IP address trace

And you can still block users from the Market too?  Impressive find!

Opening the port above also allows the market app to download software so to prevent that we are removing the market app from the tablets.


text:
Can I get a mobile view for every web page on the Internet?
Is there an app that lets you view a tiny-screen-optimized version of any web page, whether or not it was coded with this in mind?
Opera's "Mobile View" is like this, but it doesn't give satisfactory results on many pages.  Arc90's "Readability" bookmarklet is also in the similar vein.

Simply put, no.  Web pages are complex to the point where it is effectively impossible to determine what bits are necessary for the page to be usable, readable, maintain the right order, etc. for an arbitrary page.  When you couple this with poorly-coded websites containing errors and the like it becomes quite a mess.  This is why the two things you mention aren't perfect.

If you use Google Reader to read the webpages on your mobile, you can use its "Settings" to have Outgoing Links to Reformat linked web pages for mobile browsers. It works quite well for most webpages.


text:
Rename a bluetooth device?
Android doesn't seem to offer a way to name (or rename) a paired bluetooth device. For example, if I have two identical Bluetooth headsets, I can't readily tell which is which.
Do you know of any way to rename a paired bluetooth device? Perhaps an application?

The bluetooth device names come from the device itself, so unless there's a way to do this from your headset, this isn't possible, at least on stock Android. A quick google search revealed a thread that claimed CyanogenMod 7 can do this (it creates an alias for the device, doesn't change the name itself).


text:
Is the data associated with an app cleared when an app is uninstalled?
The data associated with an app which we see when we go to Applications > Manage Applications > application, is it cleared when we hit "Uninstall" or is it left untouched by the uninstaller?
The reason why I'm asking it is, I've heard from a lot of people who first hit "Clear data" and then hit "Uninstall" mostly because they're not sure so they just ensure that they get rid of the data and then uninstall!! So do one need to hit "Clear data" before uninstalling.

I'm quite sure it does clear the data, but I'll test in a bit.

Related: http://android.stackexchange.com/questions/4248/does-uninstalling-apps-leave-any-traces

As Matthew Read noted in a comment: yes, it is. The entire data directory is simply deleted:
C:\Console2>adb shell ls /data/data/com.chessclock.android/
lib           shared_prefs

C:\Console2>adb uninstall com.chessclock.android
Success

C:\Console2>adb shell ls /data/data/com.chessclock.android/
ls: /data/data/com.chessclock.android/: No such file or directory

#Reinstalled from the Market at this point

C:\Console2>adb shell ls /data/data/com.chessclock.android/
lib

The shared_prefs directory is absent in the last ls listing because I didn't launch the app, I only reinstalled it, therefore there were no preferences yet created for it (it sets defaults on the first launch). I point this out only because it illustrates that the preferences from the previous install were not retained anywhere.

This is probably obvious, but... Some apps that have the permission "Modify/delete USB storage" may use the internal memory for caches etc. and may not necessarily remove the data once the app is deleted. I've seen apps to write in not so obvious directories like /sdcard/data/[package name]/, but mostly they use /sdcard/[app name]/ which is easy to spot and delete.

Data written to the sdcard like that also won't be deleted by the Clear Data button, of course, so either way you'd need to remove it manually. Good point, though.

Simpler and convincing test...
I installed Super Sudoku, changed a setting and Manage Apps showed data.
I uninstalled it without data clearing, reinstalled it and Manage Apps showed no data. Setting was lost.
But I have read several times documentation saying that the setting will be kept after the same operation.  They must have some control of it.

It'd be better if you could also provide the link to the documentation about that, as currently it contradicts the other answers.

What exactly are you calling "that"?
I'm not contradicting the "other answers", I'm producing an experiment that comes to the same conclusion as the only answer talking about the same subject: the data memory is erased, including configuration.
The other answer says that other data may remain elsewhere.
I added that I've seen programs guaranteeing to keep the configuration after uninstallation and I don't know how (it was not in /sdcardX).  That could have been simply said in screen messages.  I'm afraid there's mostly no longer proper, complete documentation by these days.

No problem, seems there's a misunderstanding. I was referring to "documentation" that says "the setting will be kept after the same operation, and I thought by documentation means official Android SDK doc, but your comment just clear my confusion. No worries...


text:
SMS thread message total doesn't increase past 201
I have a Samsung Galaxy S running firmware version 2.2 with pretty much the default configuration it came with from the shop. On it, the (Unread/All) counter with one of my contacts has been stuck at (0/201) for quite a while, even though I've been sending more messages to the contact in question so the All value should be increasing at the very least.

Any idea how to get this to refresh so it shows the updated total?  Or is this a hard limit set somewhere or something like that?

Note: I tagged it with the phone just in case, I'm not sure whether it actually has to do with the model.

Strange bug, but ... does it matter if the # unread is working?

The number was not changing regardless...

It's because there's a threshold beyond which it starts deleting old messages. Go into messaging, hit the menu button & go to settings. The first option is Delete old messages (checked by default), and the next is Text message limit (set to 200 by default). So you've just hit that threshold & it's deleting your old messages.


text:
How can I download an APK file from the Play Store?
I can't download apps from the Play Store on my Android device (maybe due to a network issue), so I'm wondering how could I download the APK file of an app on my PC from http://play.google.com/store?

Related: Download purchased APK from play store. My answer there definitely works for "free" apps :)

Why don't you try Android-x86 project? http://www.android-x86.org/download

Sorry, I should've checked this before commenting first time. It appears that there is no official Play Store support for Android-x86. http://www.android-x86.org/documents/apphowto

You could try using an APK host like F-Droid or apk4fun

There is no easy way to download an APK file. However, redphoenix89 has found a way to download the APK with a Chrome extension. bexton did some cleanups and the result including a guide is available:

http://forum.xda-developers.com/showthread.php?t=1809458

The guide mentions that you need to disable SSL warnings, but I could download APKs even without disabling SSL warnings (Chromium 21.0.1180.81 on Linux) An updated version that works with Chromium 23 is available on https://github.com/Lekensteyn/apk-downloader.
After installation and configuration, there will be a new button in the location bar for the Android Market as can be seen below. It even works if you are not logged in on the page itself since you have entered your credentials in the APK Downloader options screen.

The Chromium extension is completely open-source (in the sense that you can unzip it and check the Javascript files) and I have not found anything suspicious.
Also note the note on the end of the guide:

Legal Note / Disclaimer
Finally, please note that the use of this Chrome extension is violating Google's Play Store TOS! You've been warned.

It doesn't work on my latest chrome version 24.xxx any idea why?

@SisirKantiAdhikari define "does not work". If you get ERROR: - Please disable SSL error warnings - Check your account information ( email and device ID ), then try removing your account and add it again. This works for me.

Did all that couple of times. Not much details on the error. It says "Error : cannot download this app". BTW: ssl warning is disabled.

Is it a paid app? For support questions please post to the linked thread.

@SisirKantiAdhikari 23> broke this extension, for a fixed version, see https://github.com/Lekensteyn/apk-downloader

@SisirKantiAdhikari  APK Downloader v1.4.0 released 19/12/12     http://apps.evozi.com/apk-downloader/

I sold my android. So what do I put for Android Device ID?

@mikethedj4 A Google Play account is required, so you need to get is somewhere (friends phone, other phone or even emulator (with some tricks)). Getting the ID is out of the scope for this extension.

I spent a decent amount of time trying to figure this out because I don't feel like having the "google experience" and as far as I can tell, it isn't possible. I've worked around it:
The F-Droid repository and Amazon Appstore are both reasonably well maintained -- either will manage any apps you install, which is handy.  That's where I start.
Otherwise, I track down and download the .apk outside of the google-run market. In many cases the Android market will point you to a developer's web page and contact information -- if they don't publish the .apk on their web page, you can always ask for it.
Two answers worth checking out:
Where can I find open source Android apps?
What are the alternative Android app markets?
PS. Don't forget: to install apps from .apk you have to turn on unknown sources (Settings > Applications > Unknown sources).
PPS. Once you have the .apk on your computer you know you need to turn on USB Debugging so you can copy the .apk to your phone, right? Settings > Applications > Development > USB debugging

USB debugging is not needed to install the apk unless you are using ADB to push it to the device. Otherwise, you can turn on USB mass storage mode to transfer it to the device and then install it via file manager app.

And in case you use ADB, enabling *Unknown sources" is not needed: simply adb install <filename.apk> does the job then.

As many others have said, you cannot download directly from the market.
Android Phones with Google experience maintain a connection to Google's servers; it is over this channel that Google tells your phone to download & install the APK.
Alternative markets & websites are certainly options - please note it can be hard to determine if the application has not been modified from the market version. You can also use USB networking or wifi. USB networking may require root.
If you have to pay for the application on the market, but don't on the other website, that's a sign that the application is probably not supposed to be there: it is at best an illegal copy and at worst loaded with malware.
(Amazon's "free app of the day" and 'getjar gold apps' promotions are example of  exceptions to this.)

As far as I know, you cannot download directly from the web Market, but you can find many apps on other app sites.

You can e.g. use Raccoon for that – a phantastic Java app I'm using:

Raccoon (source: Tutonaut; click image for larger variant)
The app requires credentials of a Google account (you can either use your own, in which case you also can access apps you've bought – or use Raccoon's companion-app DummyDroid to create an alternative profile, including fake-device, to also access apps otherwise "incompatible with your device"). Works wonderful and fast. Not only for downloading apps, but also for checking their Metadata (description, permissions, size, last update): details load much faster than using GPlays overloaded web page ;)

UPDATE: As development goes on, there are new locations:

Raccoon v4 has its Github repo here
the Raccoon Website (with downloads etc.) can be found here

Does it download split APK? Or does it download full APK? I'm very curious.

Also, when I wanted to download the latest version (3.7) there was only source code available, no .jar file, and racoon v4.x requires dummydroid which is such a pain to configure and use (android ID etc.)

@Shayan I rarely use it, so I cannot tell. But if you found v3.7 as "latest", you must have looked in the wrong location. I use 4.x for more than a year (or two). Last one I downloaded was the *.jar of 4.7 (in April this year). If you talk about Raccoon, that is :) – Oh, I see what you mean, the Github repo stopped updating with v3. Here's the one for v4, and here are the downloads (will update my answer).

One thing you could potentially do is get the android market on the android emulator (which I don't think your supposed to be able to do, but some people have done it in the past), and download the apk onto the emulator.  Then, you can find the data in /data/app/-.apk on the emulator.  Pull it off with adb, and install it on your device with adb.
But like the other answers, I would recommend finding other stores (or developer websites) to buy the app first.

You can't download apk from market.android.com . But getjar has lots of app and you can download it to your PC.

Getjar no longer seems to allow you to d/l the apk's to your PC. Or it is only certain select applications.

You cannot download apk files from http://play.google.com/store.
There are other ways to get apps (alternative markets, developer sites) and you can install them manually provided you can turn on the "Unknown sources" setting.

Well, you can; see e.g. gplaycli and Raccoon :)

@Izzy: Sure, there are tools that'll let you get APK files, but you still can't directly download from the Play Store.

Not without 3rd party tools, if you mean that – true. But those 3rd party tools do exactly that, via the playstore API. Looks like we meant the same but express ourselves differently ;)

There is an online service called APK Downloader that lets you download APKs from the Google Play Store. However, this works only for FREE apps; paid apps are not supported because of piracy issues.

Have you ever wanted to get your hands on the latest game, only to
  find that the Google Play thought it wasn't compatible with your
  phone? Maybe you don't have a snapdragon device, but youre're pretty
  sure an old device could handle it still. Have a Kindle Fire and want
  access to more than just the Amazon AppStore?
Until now you've been stuck, but a new online service also come with
  Chrome extension called APK Downloader will allow you to download an
  apk file from the Google Play directly to your desktop rather than to
  your device.

Note that the Chrome extension listed on that page is essentially a copy of the open-source APK Downloader that is mentioned in my answer, but with spyware added. As long as you use this webservice, that should be a smaller issue, but note the behavior with the extension.

@Lekensteyn What do you mean by "spyware added"? Is it not safe to use the on-line  APK Downloader ?

I won't claim that the on-line APK downloader by Evozi is safe to use, you have to judge that yourself. But taking an open-source project, inserting code that tracks your activity and then publish it without references to the original work and without notice of this spyware code does inspire confidence.

this doesnt work anymore

There have been times that I haven't been able to install an app from the Market on the phone but I have been able to get it to download by using the Market site on my computer bt telling it to install the app.  Usually the app starts downloading almost immediately.  That won't work if the router/network you are using is blocking access for some reason but the app should install as soon as you are on a network that will allow downloads.
You might try cleaning your Market data and cache. When you fire up the Market you will have to accept the Terms again.

The OP does not want to kickstart a download; OP wants the .APK on their PC desktop.

@Broam The OP is looking for a workaround to network issues of the Market on their device.  They wondered if downloading to the PC was an option; I really don't think they are refusing to consider other possible solutions.  Classic case of asking how to implement the first solution they thought of rather than asking how to solve their real problem.

Google Play seems to use some non-standard port to access the site. Some modem/router/gateway firewalls block this port by default. This is why Google Play does not work in some LANs.

Racoon is a desktop Google Play client that can download APK files from the Play store. It is a platform-independent Java app.
Total Commander (a file manager app) allows you to copy APK files of apps already installed in a device. Just copy them them to a SD card and move them to any device where the apps need to be installed.
Android Police maintains an archive APK files at http://www.apkmirror.com/. It is clean.

Available on F-Droid.
On starting the app will ask to log in. Use fake Yalp Store account:

After logging in, you'll see the updates available. There is a search button available to search apps. You can also browse apps through categories from more options. Clicking on App will provide a button to download.

Clicking on Download will download application in Downloads directory and ask to install the APK.

Yalp Store has been rebranded to be the Aurora Store.

You could also install an Android emulator on your desktop and then use APK Extractor to extract the APK.

I would suggest APK Downloader extension for Chrome as it is far more convenient. You log in with your Google Account, input some data from your phone and it will add a simple "Download APK" button to all apps on Play Store website.
If you are conserned giving your credentials to some 3rd party app, its not possible to download APK's otherwise as any tool needs to be able to identify itself as a phone with google account to get the APK. You can build a tool yourself to be sure, but that probably is not an option right now.

Might be "more convenient" – but a) doesn't work without Chrome (which I'd never use), and b) is closed-source. I rather trust an open-source tool with my credentials. And well, if c) the tool does harm me, I can go see the dev (same country and not too far region ;) // D) "its not possible to download APK's otherwise": lacks the restriction "from Google play". You can well download it from other places as e.g. F-Droid or Aptoide – my app lists often even include the links to safe sources :)

Of course, it depends on the users needs. But for me it was a few clicks that lets me later download APKs from a trusted source also in a single click :)

I didn't say it's not an alternative – we've all different preferences :) Still, you might want to update your too sharp restriction concerning the credentials ("if you want to download from Google Play").

I've found one apk-downloaders.com from which we can download apks which appearance is similar to Apk Downloader (I found sometimes Apk Downloader shows an error).
Example:

Enter package name:

Get Details & click to download apk:

At the bottom of information, you will find button for downloading apk:

Get apk:
After clicking on download button you will see the page saying:

And downloading will be started soon (within a minute):

Another (quick) way is to directly apply package name in following address:
http://apk-downloaders.com/download/dl.php?dl=<package-name>

Example: http://apk-downloaders.com/download/dl.php?dl=jackpal.androidterm

How safe is that site? Any reference that it can be trusted, and doesn't ship "enhanced versions" of the .apk files offering "additional features" one certainly does not want (backpacked trojans and the like)?

@Izzy Considerable point. This is only working site,  No reference for trusting, Use with caution at your responsibility. (I recommend not to use such site for the apps which have privacy & security concern) +1

A pity. I was hoping for some "good references" as indeed, sometimes an .apk available there cannot be found elsewhere. But I always hesitated using it as I couldn't find any reputation pointed out for it.


text:
Buy Android phone, install Android from source, have Nexus S -like experience?
I'm new to Android. I understand that although the Nexus S is built by Samsung that it has a stock standard Android image (whatever that means) and so it considered a "pure" Google phone. If I were to buy any Android phone and install a clean Android image from source (I assume this is possible... I heard it is fully open sourced) then do I effectively get a "pure" Google experience a la the Nexus S? Compared to the Nexus S, would I be lacking anything (software-wise)?

you'd be missing the drivers.

In short, you can't just install a stock image from the Google source on any phone because to produce an image, you need all the drivers for the individual phone's hardware. If you can get hold of these, then it is possible to build a stock image but a lot of manufacturers don't release them.
For simpler solution (if you don't want a Nexus S or Nexus One) get a phone that can run Cyanogen and flash the Cyanogen image to the phone. This is pretty close to the pure Google experience, in that it doesn't have carrier or manufacturer modifications on it, but does have some Cyanogen extras included.

+1 CyanogenMod brings Stock Android to many phones, plus a few extra beneficial bells and whistles.


text:
Can I lock desktop icons on X10 Mini Pro?
Is it possible to lock the icons & widgets (i.e. disable the long-press-to-move function) on the Sony Ericsson X10 mini pro?
I saw this question - Lock widgets in place - but it seems i may need to root the phone, and besides this issue, i am quite happy with the standard user interface.

Could you confirm whether you have the Xperia X10 mini pro or the Xperia mini pro?  Confusingly, they're not the same phone.

X10 mini pro, not the new Xperia mini pro.  It's running Android 2.1

It would seem as the only solution is to install ADW Launcher, as suggested in the other question.
And no, you don't need root to install ADW Launcher.
If you do decide to change launcher to ADW Launcher, Here's a link on how to lock the screen on the Complete guide to ADW.Launcher

More research shows that the beta versions required root, but it is available from the Android Market now.  I'll give it a try as soon as I've got time to play :-)  Thanks

Pity that it's not a default function of Android to simply "lock" the home screen layout.  The X10 mini pro interface is actually nicely tailored to suit the tiny screen practically.

Tried it and it actually works very well!  Thank you.

I'm glad to be of help :)

You can use Nova Launcher. In Nova Settings, Desktop > Lock Desktop.


text:
How do I convert videos for Samsung GT-i5503?
I'm using Samsung GT-i5503 with android version 2.2. I recently updated my Kies application. And after updating when I tried converting videos using Kies Video COnverter from youtube then saved in my phone, it won't play and error message was displayed(Sorry, this video cannot be played.). However, before updating my kies it works perfectly. How can I convert videos now so that can be played in my phone.

Did you use Kies to convert the videos? If not, how is the Kies version related to this question?

@Matthew: I used Kies to convert the videos.

To what extension did you convert the videos? GT-I5503 by default supports only some limited extensions.

@CustomiZer: I use the device specific setting. File type: MP4, Resolution: 320x240, Frame rate: 30, Bit Rate: 6291456

@Kyle Give MX Video player a shot. I have the same handset and I gaurentee its working pretty well.

I highly recommend Handbrake Video Converter. It can convert all common video formats to mp4,mkv that the samsung video player supports. Choose the iPod Profile which is supported by most phones or you could also create your own profile. I always use Handbrake to convert videos for my Galaxy Ace. The Samsung GT-I5503 shares many similarities with the Galaxy Ace and as Samsung is using the same Layer of Software on top of android (TouchWiz with all the Apps such as Music,Video etc..) the same settings should work for your phone.

+1 for Handbrake. My fav more-than-you-ever-wanted-to-know guide on converting via Handbrake is at Maximum PC. Just follow the instructions for iPhone/iPod.

Thanks for the tip. Handbrake works very nicely for me to convert HD mov files.

MX Video Player supports quite a number of video extensions namely .3gp .avi .divx .f4v .flv .mkv .mp4 .mpeg .mov .vob .wmv .webm .xvid and many more but it will require you to install this codecs for GT-I5503 (you will be auto prompted after you install the player but in case not, use the link).
You will not need to convert videos anymore.

+1 No conversion needed. You can also try MoboPlayer or RockPlayer


text:
How do I install an apk as a system application?
I'm trying to install an application in the system/app folder of a device. It needs to be done since I'm writing a QAT program and the tests need to run with a few privileges not available to third party apps.
I already have the device's firmware signing key and need to set the sharedUserId of the application to android.uid.system . It however keeps giving me a failure message "INSTALL_FAILED_SHARED_USER_INCOMPATIBLE" .
Any ideas on how I can fix this?

What exactly is giving you that error message? Please add the steps you're taking.

It's the package manager. One possible cause is that I'm generating the certificate myself with keytool and the relevant details provided, however the system's applications seem to have been signed with a certificate with a validity different than mine, since it was created at an earlier date. Could this be the problem I'm facing?

If you don't have root to follow the manual install procedure Demizey describes, then the app must be signed with the same key that the ROM is signed with; that's to say, the same key that the existing system apps are signed with. This is a security precaution: otherwise, anyone could write an app that would run with full system access on any device.

Found these instructions to install PowerManagerPro into /system/app, just modified them a little.
(Note: first install the app into /data/app, like you would any app, and you need a rooted device.)

Open a Terminal Emulator app and execute the following command to copy the application to the sdcard:

su
cp /data/app/your.apk /sdcard/your.apk

If you can't find the application in /data/app try /data/apps-private/.
  Then, un-install your app from the device.
Execute the following commands in the terminal emulator to remount the /system directory as read/write and to install the application into the /system/app directory:

su
mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
cp /sdcard/your.apk /system/app

If you prefer to use adb from your computer, execute these commands:

adb remount
adb shell cp /sdcard/your.apk /system/app

related: http://android.stackexchange.com/questions/4785/is-there-a-good-usb-debugging-toggle-widget-for-android/4880#4880

@Demizide: I've already tried that. I have two problems, first, the device is not rooted and is not going to be. Second the files in /system/app are owned by root and the group is also root. It somehow won't let me set the group to root, and keeps that as the shell. It's either because of this, or some other reason, the above method does not seem to work.

You may want to exploit the Master Key vulnerability.
Choose an app that, if lost or replaced, won't affect your using the device. Take its APK and find a way to modify the content of it, and and insert the files of your app. Do not overwrite anything in the original APK, but try to make 2 entries of the same file in the ZIP header. Then you can install the modified APK over the original one. It will inherit permissions from the original one, but work as you intend it to.


text:
What can cause "Android OS" process to use high percentage of battery?
I've read a bunch of forum posts about the Android OS battery drain bug. This is where the 'Android OS' process is showing large percentages in the battery statistics.
For me, I'm running 2.3 Gingerbread. I don't use bluetooth or GPS. I'm on 2G most of the time. Some days I get 40 hours out of a battery. On these days in the battery usage settings, the 'Android OS' process uses about 3% of battery. However other days I get about 8 hours with similar use. On these days the 'Android OS' process uses about 35% of the battery. I really want to find out what causes this.
The fixes suggested so far are:

Reboot (Temporary).
Turn off and remove battery for a couple of minutes.
Reset battery stats.
Change WIFI sleep policy.
Use a task manager
Flash stuff to the phone.
Revert to older versions of the OS (not really a fix).

Does anyone know the definitive cause of this problem and the correct fix? Or is it possible there are multiple issues that cause this so different things will work for different people?
Here are some of the threads:

FIX and INVESTIGATION: Android OS (battery drain) problem on Gingerbread
Fix- Battery drain 2.3.3 - high android OS
S2 Battery Drain Problem - solved for now
Issue 16721:     Android OS 2.3.3 Battery Drain

For what it's worth, I haven't seen this. Can you please add your device and carrier to your message?

This depends very heavily on what OS you are running?  2.2-Froyo?  2.3-Gingerbread?

Running 2.3 Gingerbread.

Why the downvotes? This is a legitimate question. Many Android users including myself have trouble with battery time and, by observation, on some phones battery drain is connected with "Android OS" appearing to consume more than 30% of battery charge.

I believe, there is at least one bug related to "Android OS" and battery drain. I'll outline how to reproduce the issue: (Tested with Motorola Flipout, Blur_Version.0.28.9_MB511.Retail.en.DE (stock ROM the phone was sold with), Android 2.1.)

Start with a fully charged phone.
Download the Audiobooks (free) app and launch it.
Choose a book from the free library and listen.
Send Audiobooks to the background, e.g. by clicking home button.
Go back to the Audiobooks app by the same operation you used to start it, e.g. click the icon in the app drawer. (This is the only way I am aware of to get the app in the foreground again.)
Do whatever it takes to stop the audiobook playback. (There is a "shutdown player" button, but I never get to use it, because the player just stops/disappears before I can navigate to the player screen.)
Leave the phone idle. After 8 hours the battery will be almost flat (<15%). Android's battery usage monitor attributes 33% of the batter consumption to "Android OS". The remainder is split between "cell standby", "phone idle".
Shut down the phone. Switch it on. Recharge.
Leave phone idle.
After 8 hours, check the battery status (>50%). "Android OS" does not show up as draining battery.

Whether this is a bug in the Audiobooks player or Android or both is not clear. However, this does not appear to be normal behaviour.

I just had this problem. I think what caused it was that I had removed some email accounts (but not the app) and the data continued to poll for something in "running services" in applications. This caused "Android OS" to consume up to 43% of "battery use". In less than 8 hours the phone was dead.
After the app had its "clear data" activated, I also tried it with all apps that I had installed but seldom use. It then went down to 13%! Proves that the "removed" cache data had something to do with it.
Cheers

On my Galaxy S2 media scanning stuck and battery drains completely in 8 hours at night without using.
Battery usage was like:

Android OS - 30%
Media - 28%
Display - 25%

I cleared Media Storage data and the issue resolved:

Settings » Applications » Manage Applications >> All >> Media Storage >> Clear Data

What I noticed:
media scanner starts and drains battery and my Galaxy S2 became hot quickly for long minutes when I unplug the usb connection with my computer.
It was same on 4.0.x (currently I got stock unrooted 4.1.2 on Galaxy S2).
I have a lot of media files in phone memory and on the sdcard as well.
My workaround without root (seems works):

Go to Settings > Apps > All
Find "Media Storage", tap on it
"Disable"
"Force stop"

Edit:
What I noticed since I'm using this workaround:

ringtones doesn't work
Gallery app doesn't work
Video Player app has failure as reported by wbogacz (thanks)

I miss Gallery and ringtones a bit but I'm still continuing to use this method because the media scanner problem is more annoying for me. I'll update again if I notice other differences.
Update:
Few months later I still miss the ringtones and notification sound but I can live without it. Meanwhile I've installed the Flash Notification app and I love it. :)
https://play.google.com/store/apps/details?id=com.manzy.flashnotification

This recommendation causes failures of "Video Player" to find media, and "Gallery" to display photos from the phone. Restoring Media Storage to Enable, and opening Video Player and Gallery restore useability.

It causes another problem what I noticed: I unable to choose ringtone and notification sound in preferences.

Basically you are answering your own question.
To begin with I'll go with BMitch, this is NOT a bug. There are various reasons for high rate of battery drain. Also it depends a a lot on the firmware, android version and device you are using. For example : I have a Samsung Galaxy 5 device. Initially it came loaded with Android 2.1 and a pretty poor battery life of utmost 2 days. I rooted my device and I saw a significant increase in battery life of around 3 days without charging. Next I gave a tried out a custom ROM for my handset and the battery life inreased tremendously to 5-6 days and when I upgraded to gingerbread its back down to 2 days. Also it depends on how you use your phone.

Some apps keeping running in the background and eat out battery life. Try avoiding them. Alternate solution would be using a task killer.
Excessive Data usage (over WiFi/3G) also reduces charge. Switch off wifi and turn on to 2G network when not using the internet.
Keep Bluetooth off when not using it since it also eats charge.
Turn off GPS when not using any kind of map apps.
Also there is one method many people have vouched to be working. This is be deleting the battery calibration data and forcing the system to make a new one. This however does not increase battery life. It one fixes battery mis-calibration. This app does the job.
Using some battery saving apps like Juice defender. It basically does some of the above tasks in an automated format.

Hope this explains it.

Thanks. While helpful, most of this is just general battery savings advice. I was specifically trying to find out about the 'Android OS' process. I've updated the question a little to explain better.

Okay to this question, it really depends on various factors. I can only provide instances and some cases. For example gingerbread on galaxy 5 uses a lot of battery especially when the orientation sensor is on because the refresh rate of the screen increases abnormally. Similarly each ROM will probably have it own reason. You should probably question the dev team of your ROM.

many badly coded apps on loss of network continuously keep polling till connectivity is restored, this can cause massive battery drain.

Another reason your cell phone battery can die quickly is that your cell phone is being monitored or bugged by be someone who had to download a spy program which runs in the background all the time. And depletes your cell phone battery quicker. Check for suspicious programs on your phone.

This is true, battery depletion occurs for any background process. Labeling or pointing deliberately to a "spy" program for instance, leads me to suspect you have not considered the nature of "spying", which is a covert activity. Anyone placing such an app covertly would want it to be as slight an impact to system draws as possible to be more effective.

Start by not calling it a bug.  There are lots of causes of battery usage, just like there are lots of things that will cause the electric meter to spin.  A short circuit needs to be fixed, just as a bad application needs to be removed.  A task manager is similar to having someone run around behind you and turning off the lights.  And various settings can be tweaked to get more out of the existing system, just like you can switch to CFL bulbs.  There's no one fix, because there's no one reason.

Really looking for something more specific as to why the Android OS process would be using such a high percentage of battery?

@sickgemini, OS = Operating System, not a simple thing with a single switch.  Some people have issues with misbehaving apps not suspending, others have hardware issues, or perhaps a network problem.  Everything touches the OS and the OS touches everything, and should one of those things malfunction and get in a tight loop, it will eat CPU.  There is no easy "specific" answer that will solve the problem for everyone.


text:
Is there an Android app that scans a device for vulnerability issues?
Is there an application that scan the phone or the phone image searching for vulnerability issues?
In the internet there are several tools that make Network scanning, but I found nothing specific for Android.
Any ideas please comment, I'll be very grateful.

If you connect your phone to WiFi, it will acquire IP address. So you will be able to scan it's network services for vulnerablities from your desktop PC with convient programs.
I like NMAP port scanner and ZenMAP shell for it.
Also it looks like guys are porting NMAP to Android. Link 1, Link 2

Aside from open ports that a network scanner would find, you may also be vulnerable to certain local exploits. The somewhat recently released X-Ray app is designed to check for a number of known vulnerabilities (though it is not capable of fixing them - you'd need an updated version of Android for that).

Huge edit.
Almost all of the "one-click root" methods exploit a security hole; it's usually a privilege escalation exploit to get "temp root" as a first step. (From there the scripts will go on to make /system read-write, allow writing to partitions that are normally read-only, etc., in order to keep root access across reboots.)
Obviously, if you can break the security of your phone, someone else can too.
TL;DR: If a root method exists for your phone that does not consist of "unlock the bootloader and flash whatever you want" -  you have a security vulnerability.

Root alone doesn't cause vulnerability.

Let me try rephrasing my answer.


text:
Bluetooth headset doesn't play ringtone
I've paired Bluetooth headset Plantronics Explorer 390 with Android phone. I can set ringtone of incoming call on every contact. The issue is that any Android phone I've tested plays ringtone on internal speaker. In headset I hear at this moment standard beep-beep-beep. Is any way to send ringtone to BT headset?
Of course, BT headset ideally works in other terms: when I answer the call, sound output is redirected to headset as I expect and phone is using mic in headset.
But on every Nokia phone ringtone is correctly redirected to BT. It is very disappointing that newer and more functional Android lacks this feature.
I've tested next phones:

LG Optimus One P500
HTC Inspire 4G

I've tested different versions of firmware. From 2.2 to 2.3.4. The behavior is identical.

The same behaviour appears on my Samsung SBH170 and Galaxy S. Can't remember ever, on any phone, hearing the ringtone through the headset though, it's always the built-in beeps.

On Nokia 6230i and Nokia 5310 ringtone is played through BT headset. So there are such phones. But they are based on different OS.


text:
VNC viewer shows only black screen, but sends events to droidVNC
I am using a VNC server on my Android device (droidVNC it is called.)  I have tried using multiple VNC viewers and each one has the same results:

the viewer window is a black screen (sometimes a blue screen.)
clicking on the viewer correctly sends the events to the phone (I can see the screen change, etc.) but it is just blind clicking and pretty unusable.

I think that since this is the same problem on multiple different viewers (TightVNC Viewr, RealVNC Viewer) that it is a problem with droidVNC server.
Do you think the problem is actually with the VNC Viewer?
Has anybody experienced something like this before, and are there any tips you can give to make the droidVNC server run faster/better?

The Nook running CM7 has this problem for a while with both VNC and screenshot programs like ShootMe.  IIRC, the solution was a boot paramter change to alter framebuffer size.  You could give ShootMe a try and, if you get black screenshots, you know it isn't VNC.  Unfortunately, if it is the framebuffer, you're out of luck.

Hey Earl, thanks a lot for the comment. ShootMe (which turns out to be called PicMe) works great. And actually, it seems to be its own VNC server, because clicking the "Live" option lets me send key events and move the mouse. Thanks again, if you want to post an answer I'll accept it.
@Selvin thanks for the android.se link, and if you have suggestions for the tags I will update them.

I think the problem is with droid VNC server. I have faced the same issue recently and the project seems to be abandoned (app last updated on June 11, 2012).
Then I tried different options under Settings->Display Access Method. The default option is auto-detect. I changed it to Framebuffer. Restarted the server and I could see the display on my viewer software. You should try all options till it works.

Tested on my ancient phone GT-S5360 running Android 2.3.5 (Better options available for recent android versions but they don't work on 2.3.5. So, I needed to find a solution by any means)

This was quite a bump, but I've also searched for ages for a good and reliable way to get the display and send events to android phones, and never had too much success. Pretty much every solution relied on an app on the phone, and they were quite laggy (like VNC usually is).
This all changed when I met scrcpy.
As the developer, puts it:

scrcpy provides display and control of Android devices connected on USB (or over TCP/IP). It does not require any root access. It works on GNU/Linux, Windows and MacOS.

All that's required is ADB debugging enabled, and you're basically good to go. You can set the bitrate, the scaling, everything. But most importantly, the latency is ridiculously low.
If you're looking for a similar solution to this problem, I'd give it a go. I know I'll be never fiddling with remote desktop servers and clients anymore!


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Not enough time for GPS lock for geo-tagging when taking a photo
I turned on geo-tagging for photos, but the problem is that the GPS locking procedure seems to only start when I open the camera app - but it takes minutes for it to lock on a location and by that time the photo opportunity is gone.
Is there any way to enable GPS lock to be ready even before opening the camera app? For instance some phone settings to toggle it off and on, or some service I can get which continuously runs in the background and maintains a GPS lock?
And if there is, what will be the power implications of maintaining a GPS lock? Does it drain a lot from the battery, or is it relatively benign?
My device is Samsung Galaxy S 2, running Android 2.3.3.

Ooh, good question. Maintaining a GPS lock generally uses a fair bit of battery.  What phone do you have?  Many phones have built in GPS test modes that would likely work for this, but they're manufacturer- and often device-specific.

@Matthew added my device details.

Have you tried just taking the photo? Does it store any coordinates in the photo details? I'm thinking (if they designed it well) it could take the photo immediately then update the coordinate details when the lock is achieved.

@sickgemini I looked at the image details and it says "Location: Unknown location, Latitude: Unknown, Longitude: Unknown"...

I often fire up the GPS status app, wait for it to get a lock and then switch to the camera app (without closing GPS Status). GPS Status seems to get a lock a lot faster, forces download of the GPS assistance data, and also gives you much better feedback while a lock's being acquired. https://market.android.com/details?id=com.eclipsim.gpsstatus2

I've found that if I'm using another app in the background that polls for location (e.g. latitude in Maps) I tend to get much more accurate geo-tags in photos. YMMV, but perhaps if you know you're going to be shooting photos you can open up Maps or similar first to start the process going.
WRT your battery life question, leaving maps open tends to destroy my battery in a few (5-7) hours (Dinc 1, known for horrible battery life anyway, even among android phones), especially if I'm shooting a number of photos. When I know I'm going to be using my phone in that manner I typically bring a second battery along, so that when I'm done I can still make calls.

I'm starting GpsFix before any app that use GPS
https://market.android.com/details?id=com.androidlab.gpsfix


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How do I know when updates are available for my phone?
I've got an Optimus T, and being new to the world of Android, I'm confused as to how I'm supposed to update my operating system.
The phone is carrier locked to T Mobile. Does this mean that I can only get updates from them? Can I tell the phone to look on another server? How can I tell if I have the latest build of Android that's available for my device?

This may be helpful: http://android.stackexchange.com/questions/13510/how-do-i-update-the-os-in-my-device

To check for phone updates, go into Applications > Settings > About Phone and tap System updates or check for updates. However, if a new update comes out, then you should get a notification informing you so and giving you update instructions. If you root your phone, then you could install unofficial updates that are not from T-Mobile. There are instructions at http://forums.androidcentral.com/t-mobile-optimus-t/43138-how-root-lg-optimus-t.html if you want to do so.

When I check I'm told that the server is unavailable.

That's weird... Make sure that you have a network or wifi connection.

Oh, I do. I'm on WiFi.

That's really weird...

To copy from Al's answer here:

If there is an official update to Android 2.3 (check the post on Gingerbread updates) then you'll get a notice on your phone (eventually). Just follow the instructions.
If there's not an official update and you don't want to wait for one, you'll need to root your phone and install a Custom ROM.


text:
How much internal memory after updating HTC Desire to official Gingerbread?
I'm very tempted to upgrade my Desire to official 2.3.3, but I was wondering if I'd lose internal memory in doing this. I didn't find any info on the Internet, so I would like to ask that to someone that actually upgraded how much free internal memory there is after the process.

I found a user reporting 123 MB of free internal memory after the upgrade, vs 134 MB on a stock FroYo, so you lose 11 MB when upgrading, although it seems that applications take up less space and app2sd is more efficient. I'd like to hear more stories though.

I am surprised that there isn't more to find on this subject.. I was going to do a factory reset, so I thought I might as well update.
After the update I installed almost all the apps that I had before, and instead of 15Mb free (that I used to have), I now have 75Mb free :p

In the end there is less space than with 2.2. I'm not sure how much, but truth is I can install less applications. I think I'm going to install Cyanogenmod.

Gingerbread is totally buggy about free space.
I've even used A2SD, and moved that Dalvic Cache to ext partition OK. I got an extra 80MB, but that amount is decreasing each day. I am sad a bit about this.
I would recommend that you root your devices and go back to Froyo.  I  need to use an  application which needs android 2.3 and on Froyo I would not able to install it.
I am sad because I like my HTC Desire. I don't consider it to be so old that it should be replaced by a new device.
What can we do? :-)

So many strong statements without any reference.

What kind of reference would you like ? Have you tried that rom?

I happen to have the same experience. I even wrote about it in a post on my blog. The problem is that Android keeps eating space over time and there's no way to get it back but to wipe all user data.


text:
Angry Birds and other games force close (crash) on startup when using Simple2Ext (S2E)
I'm running CM 7.03 on my HTC Desire (GSM) and have successfully partitioned my SD card with a 512mb ext4 partition. I installed S2E and it moved my apps to /sd-ext successfully, but certain apps now crash at startup. Angry Birds, Cut The Rope etc will force close as soon as they're launched. Other apps work just fine. I'm assuming it's apps with native code that have issues, as pure Java ones seem ok.
Has anyone else experienced this problem, and if so, how did you fix it? If I can't find a work around, I will have to delete my partition and just put up with small storage space.

I would try backing up the data for one of the apps, then clearing it and seeing if it works afterwards.

You sir are a genius. If you'd like to post this comment as an answer, I will gladly award you 15 internet points.
The only downside is that I've now lost all my save games for Angry Birds, Cut The Rope etc. At least they're working though :)

Hahaha.  Done, gimme my internet points :P

I would try backing up the data for one of the apps, then clearing it and seeing if it works afterwards.
You could try just restoring /data/data/com.rovio.angrybirds/files/highscores.lua and see if that works.  I don't have Cut the Rope so I don't know how its files work, sorry!


text:
Looking for option for 3-way file sync
I want to be able to have a 3-way sync for some files between home and work PCs and my Android (HTC Sensation, 2.3).  I want to sync a few documents and Keepass password database.
What options are there for this?  I found SMEStorage which looks very good, but I can't really see a good sync provider that does everything I need:

Windows Live Mesh: good for transparent sync on the PC, but I did read somewhere that docs synced from here would be read-only on Android (this doesn't apply to Skydrive, but can you sync to that like you can with Live Mesh?)
DropBox - hmm, I really don't want all my files publicly readable thank you...
FTP - I'd have to have a separate sync solution on my PCs
Google docs - not good on PC as I want a physical copy synced one each one.

Is there some other simple method I'm missing?  If there was a way of getting it to work with Live Mesh then that would be ideal.
EDIT:
  Looks like Live Mesh also syncs to Sky Drive, so Android clients that have read/write sync to Sky Drive may work, such as Sorami or SMEStorage may work

DropBox (with the exception of your "Public" folder) is completely secure...
Other Dropbox users can't see your private files in Dropbox unless you deliberately invite them or put them in your Public folder. Everything in your Public folder is, by definition, accessible to anyone.
https://www.dropbox.com/help/27

Completely secure apart from this: http://www.theregister.co.uk/2011/06/21/dropbox_security_issue/

it was only unsecure for four hours.

@the_mandrill: security fuckups like this can happen to any provider, including if you had your own FTP server (well, especially if you owned your own server). I don't think this knee-jerk reaction is warranted.

I use SMEStorage. I actually use 2 Storage Clouds on it. My home WebDav Server and SkyDrive.
My files physically reside on my home WebDAV server and on SkyDrive. I have a phone to SkyDrive folder sync setup through the SMEStorage App for some docs/files.
SMEStorage has the ability to encrypt files uploaded to it and then decrypt on the fly from the  Client, which suits me. It uses AES-256 and does not store the private key so if you lose the key your stuffed but again this approach suits me.

Thanks. I did go for SMEStorage before I saw your response. It looked to be the most versatile option that seems to cater for every platform and storage mechanism.

You can add your own private folders to Dropbox, you don't have to use the Public folder. I use this for some syncs between work, home and phone.

Thanks, but I'm concerned about Dropbox's security - see above comment

@the_mandrill you could always encrypt the files yourself that you put on Dropbox

I could, but then that defeats the idea of having transparent client sync at each end as that necessitates having to decrypt, edit and then re-encrypt

I use Sugarsync.  Similar to Dropbox but without the poor security track record.  The Android client also handles automatic sync where dropbox doesn't.  Of course the Windows clients do as well.

Google Docs actually would be a viable solution. You just need a way to sync local files to and from GDocs.
ReadWriteWeb reviewed three such apps. There are surely others.

i am using aerosync to sync a folder over various devices , it works well and it's free and unlimited storage on any number of device but no cloud storage , it's having client for all platform


text:
Help Uninstalling Stubborn Application
I have the original Motorola Droid. I recently installed Lotus Notes Traveler on it (we use Lotus Notes at work). The application is giving some issues, so I was going to uninstall it and re-install it. Unfortunately, when I try to do that I get a message the message "Uninstall Not Succesful". Is there any way to uninstall an app that does not want to uninstall through "Manage Applications"?

Are you rooted?

No, I have not rooted this phone.

Apparently the Lotus Notes Traveler app makes itself the Device Administrator on the phone.  You need to disable this before uninstalling it.  The following quote is from Lotus FAQ:

You should uninstall Lotus Notes Traveler by launching the Lotus®
  mobile installer application, then selecting the Lotus Notes Traveler
  application and choosing uninstall.
If you choose to uninstall
  manually and your device is running Android 2.2 or above, you must
  first disable the device administrator. To do so, select Menu >
  Settings > Location & Security > Select device Administrators. After
  you have disabled the Lotus Notes Traveler device administrator, you
  can use the operating system to remove Lotus Notes Traveler, by
  navigating to Menu > Settings > Applications > Manage Applications.
You can uninstall Lotus Mobile Installer using the normal method for uninstalling
  applications on your Android device.

I would install the Android SDK on your PC and attempt the uninstall through ADB:
adb uninstall packagename
packagename is probably something like com.ibm.lotusnotes, I don't know the exact name since it doesn't appear to be publicly available.

I managed to finally uninstall using Titanium Backup's Force uninstall feature

If you have ROM Manager installed, try doing a "Fix Permissions"

Fix Permissions from ROM Manager requires root.  According to OP, his phone is not rooted.


text:
Skype sound volume
I have Android 2.1update1 and I installed Skype from the Android Market.
In many times when I use it to talk to other people using Skype the talking volume is too loud!
How can I turn it down a little bit?
I just didn't find any volume settings regarding Skype.

Use regular volume button on phone that you use for phone calls or music

you mean the two volume adjusting buttons on my phones left side, that sets the "ringer volume"? - no, it has no effect. :(

What mobile phone you have? (I'm just wondering why you still on 2.1)

LG GT540 & Samsung GT i5800

You have to adjust it during the call, not in the menus.

When i adjust volume in Skype, it tells me i'm adjusting the In-call volume, which is (believe it or not) the same volume setting used when you're in a regular phone call. If you can't adjust this through the settings, i'd try making a normal phone call, turning the volume down, then trying a call in Skype and seeing if the call sounds have changed.

New version of Skype uses system volume for calls. So change there in system preferences and volume in Skype will be changed too.

I tried all sound adjusting settings in the menu, but with no luck. it's always the same sound volume (in a Skype Test Call). Where exactly is this "System Volume" in Android? please tell :) ty!

It depends on your Android version. Usually it is somewhere in Settings->Sound->Volume menu.

"Android 2.1update1" - I tried all the "volume" adjustments in settings. i think this is a bug. :)

Try another firmware. Also if you use unofficial ROM, please clear everything you can during update.

I use the offical firmware. I don't want to use un-offical, trojaned firmware. :P


text:
Can I record Google+ Huddle chat messages?
I thought they have being saved at Gmail chats like google-talk. But I was wrong.
How can I record Google+ Huddle messages? Saving at gmail will be best option.

There's currently no way to do this. Maybe suggest it on the google forums?

There's no way to do this but you can take screenshots of the chat and save it like that. There are a lot of screenshot apps on the Market, some require root though.


text:
Unlocking Xperia x10 using a jacket
I have passed the limits for attempting passcode / sim code. Someone has advised me that I should use a jacket to unlock the phone (Xperia X10a)
Where do I get the jacket from? Also, will the jacket solve my problem?

When you say "a jacket", do you mean "a JTAG cable"?  http://en.wikipedia.org/wiki/Jtag
Such a cable will most likely not help you.  Your best bet would be taking the phone to your carrier where they should be able to SIM-unlock it for you.

I don't know about the jacket. I asked a cell services provider if I can get the unlock code. He told me that I if 2 options for unlocking the sim either through code or using a jacket to unclock it. That's is my question if there is something like unlocking the phone using a jacket for the sim card

Don't mix things here. From your posts it looks like you have entered your SIMs PIN to often and need now to enter your PUC/PUK. This has nothing do to with your androids phone lock. In Germany it's common practice to receive the PUK together with the SIM card. If you have no PUK you can only ask your SIM provider for the PUK or a new SIM. I am not aware of any other method to unblock a blocked SIM.

You've misunderstood your operator.  There is no such thing as jacket for the phone. Either you misinterpreted the support guy, or he is just incompetent person.
If you have locked your phone you have two options:

Official phone manufacturer representative can help you with resetting the phone to the factory state.
If you don't want to mess with official support (sometimes it's a waste of time), you can try to unlock your phone manually using just usb cable and commercial software tool (DaVinci, for example - I've used they service couple of times). If this will fail you can always fall back to the option one. Please note, however - trying to unlock your phone manually you can lose your warranty.


text:
Why does Navigation keep choosing a different route?
I have a route which I have taken a couple of times using Google Maps navigation and every time I go it takes me one of 3 different ways, even though I start and finish with the same location every time.
In web Google Maps the directions returns 3 results which are 35mins, 40mins and 41mins with varying routes, one is using 3 motorways, another is motorway-town-motorway and the last is through the "backroads".
Is GNavigation making this decision intelligently (traffic reports, time of day etc) or randomly picking me a route of the 3 available? This is in the UK.

Try turning on the Traffic layer before setting off, that should give you a bit of a visual idea whether there is any major traffic that Navigation is trying to route you around.

Google Navigation uses traffic information in some countries, e.g. USA and UK. If you are in one of those, yep, it will pick an optimal route based on traffic.

+1 if traffic info is available, it will use it to try and route you around any heavy traffic.


text:
why HTC wildfire phone deleted all of my sms for 2 times?
my HTC wildfire phone deleted all of my sms suddenly. I don't know what happened!!
and I hadn't made a backup of them. what can I do to restore them?

If you are using the stock messaging app, the settings might be the cause of the trouble.
Go to Messaging app -> Settings -> Untick Delete old messages. (If it was ticked I'm sure that was the reason for auto deleting of the sms)

There are two moments. 1. Default setting is to save all messages an do not delete oldest. 2. Messages are deleted not all, only oldest. So this isn't the case of topic starter.

In my default setting on Gingerbread the option was ticked and all my messages were deleted as a result of not using sms for quite 10 days. The setting depends on the ROM the user is using. But in this case I might be wrong, but it has occured.

It's a known bug in the Android OS. There is nothing you can do about it but bump your head. I'm moving over to  iOS because of that. There are many other bugs in Android, but this one is a deal breaker for me.
Here is a link to the official bug report. The issue has been known to Google at least since 2009:

(other comment transformed into an answer) Please note: This problem is probably caused by bad flash cells. The used database solution on Android is SQLite. iOS also heavily relies on SQLite (including SMS storage). This kind of problem will happen on your new iPhones too at some point probably. Do backups.

Someone posted a logcat snippet of the occurrence in this bugreport:
I/Database(9): sqlite returned: error code = 11, msg = database corruption found by source line 54710
E/Database(9): Removing corrupt database: /data/data/com.android.providers.telephony/databases/mmssms.db
E/DatabaseUtils(9): android.database.sqlite.SQLiteDatabaseCorruptException: database disk image is malformed

Explanation of the above:

SQlite is the used embedded database engine on Android. Error code 11 describes a malformed database disk file (#define SQLITE_CORRUPT 11 /* The database disk image is malformed).
A bad db file was detected, removed and a new empty one created
All SMS are gone now

Some further thoughts:

SQLite is known to be extremely well tested (99.9% of all code are test cases)
Therefore it's highly probable it's not SQLite which causes this
Very probably the file got corrupted by bad flash storage cells, memory corruption or another reason

You can do some things. I'd suggest the following order:

See again if you do have a backup. If so restore it.
You could take your phone to a forensics / data rescue expert like Kroll Ontrack and have it analyzed.
There's also growing free support for mobile devices, eg. by Sleuthkit
For the future: Back up your SMS data, e.g. move them to GMail

Some final words:
SQLite is very common for embedded devices, iOS also relies on SQLite for many things (including SMS storage). There will always be a chance of losing data if you don't backup: Device is lost/stolen/broken, dying flash storage cells, software bugs, other erratic situations like full storage, etc. It's the same with any device, don't rely on a single point of failure, have a backup in the cloud. This just works with mails, your address book and so on. Do the same with SMS.

Nothing. You can do nothing. One option is go to data recovery service, but price will be uninteresting.
Also tell please if you install 3rd party software on your phone.

why HTC wildfire phone deleted all of my sms for 2 times?

I suppose that there can be installed glitchy or malicious programs on phone. Also if you have child or children, they may have played with phone and occasionally deleted messages.

Why is the only sane answer downvoted?

I don't know... Somebody likes to press downvote for every answer. Some kind of terrorism :-(

This has happened to me multiple times before. Each time the number of messages was around 6000. I think there may be an upper limit on the number of messages the Messaging app can handle, and beyond that it just deletes everything. I might be wrong though.
I don't know of any way to recover the messages though.

You're really asking two questions here, and both are extremely hard to answer. First of all; why did the messages disappear? We can't possibly know this because we know nothing about what software you're running, if you changed something (installed/removed software etc.) around the time the messages disappeared and so on. Maybe it's a "feature" of the stock software?
The second question is; how can the messages be restored, and that's a very hard question to answer because what you're asking about is data recovery which is not exactly easy work usually (that's why it will cost you a lot of money to pay someone else to do it). You would need to make a copy of your entire storage first of all, and then go in and look at the raw data to perhaps salvage all or some parts of earlier messages.
In short, if you care a lot about some messages, you should have them backed up to begin with. You can either do a backup of your phone, or copypaste the messages into a platform in the cloud (Dropbox, Google Docs, you name it).
I'm sorry to say you won't find a solution to this problem without either paying a lot of money to get someone to recover your data, or start reading up on data recovery yourself and learn how to copy all the data from your phone bit by bit and then looking at the raw data.
I wish I could have given you a better answer, sorry about that.


text:
Why does viewing an .htm file in Android dropbox folder show broken images?
I have an .htm file in a dropbox folder with the following content:

this is a test of html

When I view it on my PC, it shows the image (which is in the same directory as the htm file).
However, when I view it on my HTC Wildfire and choose as the viewing application "HTMLViewer", it shows me the correct HTML rendering (with bold) but shows me a broken image.
How can I view HTML files with image tags in my dropbox folder on my Android phone?

Similar problems has been reported (though it is 1 year old). I'm guessing the issue is with the app. Doesn't your default android browser open HTML files ?

Is the image actually on your device? The Dropbox app doesn't automatically download files to your phone, it just lists the files on your account. You need to open a file (or long-press and hit download) to actually get it on your device. I tested this and as long as I download the image first it works fine. If you enable the file status icons in the Dropbox settings anything without a green check has not actually been downloaded to your phone yet.

@eldarerathis that was a good idea, but even after loading the image onto my phone the html page still shows it is broken, as if there is something wrong with the path, i.e. as if there is an absolute path, strange.

@CustomiZer when I hold my finger down on index.htm, then choose open, it gives me the choice between (1) Text Editor DB, (2) HTMLViewer, (3) HTML Visualizer DB. How do I tell it to "use the Android browser?"

I did some testing on different handsets and discovered that some like mine allow opening of htm file using default browser (dropbox not installed) and some gave an option like text, HTML viewer. I'm not really able to understand the cause of the problem. Try some other webpage and check if you still get the broken images.

I have DropBox installed on my Moto DROID v1 (Android OS 2.2.2).  I placed an HTML file that referenced an image in a DropBox folder.  The image was in a sub-folder.

DropBox\Folder\index.html
DropBox\Folder\img\image.jpg

I first downloaded just the index.html and opened it in the HTMLViewer.  The image link is broken.  I then downloaded the image.jpg file, then returned to index.html and viewed in HTMLViewer.  The image now appears properly.
I'm not sure if it has anything to do with it, but you may want to try switching your file extension to .html, and verify that the doctype of your file is set properly:
<!DOCTYPE html>

The Dropbox app for Android doesn't save files to a "folder" like the PC version does. Android has stronger security and doesn't let apps access other apps' files, so even if it did do that, the browser wouldn't be able to read the image.
When you choose to open a file that's listed in Dropbox, the Dropbox app creates a special URI that points to that one file. It uses an intent to start an activity to view that URI, and sets a special flag to say that the new activity (in this case, the web browser) has permission to access only that URI. That means that there's no path you can put in the HTML file that lets the browser read the image: it has Dropbox's permission to read only the file you clicked on.
If you want to have a directory of HTML files and images that all load in the browser, you need to store it on the SD card (rather than in one app's data) where any app can read and write any file. I don't believe the Dropbox app has the feature of being able to sync directories on the SD card, but you could use another app to achieve that. For example, you could use an FTP client to sync the directory with one on an FTP server.
The answers to this question have lots of suggestions for how to keep directories in sync with Dropbox or another server.