text:
Why doesn't my Nexus 7 synchronize since Android 6?
Normally, Wifi is deactivated on my Nexus 7 to preserve battery. I'm mainly using it to read and watch videos when I'm commuting so I don't have Internet most of the time when I'm using it.
I'm using Tasker to switch WiFi on between 5AM and 5.10AM so my tablet can synchronize everything once a day. This worked perfectly before: in the morning, I have all current emails and Apps are updated frequently.
Unfortunately, this doesn't work with Android 6 anymore. If I'm correct, WiFi does switch on, but it doesn't connect to the wireless network. Maybe this has something to do with the new battery saving techniques, if the screen is off, WiFi is not actually connected.
I tried to extend the period by 5 minutes and added another task in tasker to force a connect, also doesn't work.
Does anyone experience this behavior too? Any ideas on how I can force the tablet to synchronize everything once a day even if the screen is off?
Thanks
Update:
This night, I had my tablet plugged in and surprisingly, synchronization worked! I found an option in the advanced WiFi setting to keep WiFi active always or only when plugged in. This setting is on always on mine, so that shouldn't be the issue. Any other ideas?

Good point, I don't think they have. But i did try the profile while my screen is on and that still works correctly.

Meanwhile, i can answer my own question. Found a description from Tasker that explains and solves the problem here http://tasker.dinglisch.net/userguide/en/androidpowermanagement.html
The important part for my Nexus 7 with Android 6:

The location of the setting may vary per device, but a common method is to launch the Android Settings app, select Apps, click the cog icon top-right, then Battery optimization. Click All apps, then Tasker, then Don't optimize.

Didn't know this menu, good to know for other apps too.

They call that battery optimization, doze mode.


text:
Unable to remove malware
I have android tablet and every time i open a browser, any browser, it automatically opens pages with ads or making me download things. Obviously the tablet got a malware but i am not able to remove it. I installed Avast, Avira, Malwarbites, CCleaner but none of them was able to remove this malware.
Any other ideas how to get rid of this malware?
Usually in which location the viruses for android resides? In Windows most of them are in Temp folder but i am not very familiar with android.

The best way to remove ~99% of all malware is to simply factory reset the device. Only a small fraction of malware apps really protect themselves from those solutions, because they require more work than needed for their purpose.

Isn't that a little drastic solution? I mean if i reset the device i will loose all of my settings and apps i have installed, right?
And by the way, i am seeing ads on every other app i open, they appear at the top or at the bottom of the screen.

I know from a friend, that this is the easiest way to remove any malware. Plus, it allows the system to reconfigure itself and usually restores some of the original speed it had after the first boot. You could always try to find out if you have any suspicious app on your device and remove it by hand.

What tablet do you have? Also, save all your important files before you consider factory resetting.

The tablet is not a top brand, but the android version is 4.4.2.

Seems it's related to the recent Alarm Controller malware. If it's, related post: http://android.stackexchange.com/questions/129052/alarm-controller-is-sending-me-unwanted-notifications-ads

I reset the factory settings: settings>backup&reset>factory data reset and now the ads disappeared. I also checked "opt out of interest based ads" in google settings app.

Please edit your answer to include steps you used so others may follow along. Also to make it a complete answer.

"Opt-out of interest based ads" won't help this issue actually. It just instructs Google to display any ads, not related to your interest based on your history.

Most of the malware removers for Android are of limited value because Android makes things run in their own little sectioned-off area of memory. Sometimes, a malicious app may slip through the protection or trick you into allowing it past.  Unfortunately, the same setup that tries to block malicious apps also will prevent "good" apps from trying to fix it.
One of the easiest ways I can think of to force you to default to a malicious web page is either changing the browser's default web page or creating shortcuts on your home screen so that you think you're starting your browser but you're actually going straight to the malicious web site.
First of all, try launching the browser directly from the Apps menu (where you go to see all the apps installed).  It may be that the malicious software created shortcuts on your home screen that look like browsers but aren't.  If launching it from the Apps menu works normally then delete all the copies on your home page and drag the App from the menu to create a "fresh" one.
If that doesn't work then something may have changed all the browers' home pages.  Go into the settings for each browser and look for an option to set  your home page (there's a bunch of different terms: home page, default page, starting page.  Look for something like that) and set it something innocuous like Google.

The spams and ads didn't just come out of nowhere. Many times it's the junk app that you have downloaded. Crappy apps produce spam, ad, makes your phone act up, lag, etc.
Sounds like you have an app that produces needless ads. Go over what apps you have installed, and nit pick through them, and uninstall the app that you would think to be producing the ads.
another best way to remove malware from an Android would be to, unsurprisingly, install a malware removal app. Just be sure to install a reputable one. How silly would it be if you accidentally installed malware while trying to install a malware remover? Here are some free ones that you may want to check out:
3 60 mobile security.
Avg mobile security.
It will surely help you if not then try this
Back up all your pictures (and music and videos) to your Google account. Google+ is a great place to store your pictures, drop your videos in your YouTube account, and you can store up to 20,000 songs in your Google Play Music account. Utilize this free space Google gives you, even if it's just to store a few things while you pour digital bleach on everything.
Take the SD card out of your phone if it has one. Visit a computer and wipe and repartition it using the built-in software for disk management. Don't save anything — you need to be brutal to make sure anything nasty gets nuked. But first try Checking your app list. Then use tool if that's not helping.

How shall that help removing malware? Are you suggesting malware just sits in the cache folder? I very much doubt that. Your suggestion doesn't hurt – but probably doesn't help either.

Wiping cache didn't help. Still looking for other solutions to try, before reseting the factory settings.

Check the answer now

Please refrain from your condescending editorial comments when providing an answer. Just provide facts, references, links  and/or personal experiences. Unless edited this should be a comment, not an answer.

source: Stack Exchange

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

sort: votes


text:
Unbrick Galaxy S5
I tried to install a CWM recovery on my G900F with Odin Mobile (using these instructions). But when the phone restarts, it just shows this:

It says Recovery is not seandroid inforcing, Set Warranty Bit: recovery. It reboots avfter a few seconds, but then the same text is showing again.
First of all, what does it mean?
Second, any idea of what I should do?
By removing the battery and pressing volume down, home and power when returning the battery, I can get it to start in some Download mode, but I don't know if there's anything I can do. It says:
ODIN MODE PRODUCT NAME: SM-G900F
CURRENT BINARY: Samsung Official
SYSTEM STATUS: Custom
REACTIVATION LOCK(KK): OFF
KNOX WARRANTY VOID: 0x1 (2)
QUALCOMM SECUREBOOT: ENABLE (CSB)
RP SWREW: S1, T1, R1, A1,
P1 UOC START
Some forum posts suggest try flashing again, but when I connect the device to my laptop (Mac), it won't show up when i list devices in adb or fastboot.
Is there anything I can do?
(I've done this a few times before, but I still consider myself a beginner ...)

Hey, if I get an explanation for the downvote, I promise to write a better question the next time!

Ok, I solved it at last. What I didn't know, was that with Odin, i can flash a custom recovery to the device, even though it didn't seem to respond to anything. Next time, I'll try Odin directly.
Here's a good guide, if someone else is interested!

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


text:
Decrypt crypt7 without key (phone was factory reset)
I have my whatsapp backup db in crypt7 format. I forgot to backup the crypt key.
Now I want to decrypt the crypt7 file but not sure what to do. I have my device with me on which the file was encrypted, but the device has been factory reset, hence I am unable to get the key from it.
Now my question is, if I reinstall whatsapp, will I be able to get the crypt key and will I be able to decrypt the file which was encrypted before factory reset?
if not, is there any other possible way to decrypt it?
Thanks for any help.

As far as i know the whatsapp crypt7 files are not actually encrypted.
There is an app that can encrypt/decrypt/backup the crypt7 files without a key.
Also, over copy-pasting your whatsapp folder will also work, i think i've succesfully tried that already...


text:
Is the external storage size limit hardware or software?
AFAIK, All phones I know have a SD Card size limit. Is this hardware, or software ?
If this is hardware, what changes between, let's say a 32GB card, and a 64GB card ?
If this is software, is this just an arbitrary limit, or the system really won't be able to read it ? Is this changable (Custom ROM, Kernel) ?

As I know, this is a software limit. The communication protocol of a 32GB, 64GB or even 128GB SD card is exactly the same. Only the old non HC or XC cards of 2GB or less uses a different communication protocol. The reason that some devices doesn't support 64GB or bigger is due to the use of the exFAT file system on cards of 64GB and larger. Although, if you reformat this cards to the older FAT32 file system you can use in a device that officially supports up to 32GB cards (only in very rare cases it still doesn't work). My experience is that a 128GB card formatted in FAT32 works without issues in a Samsung Galaxy S2 that officially supports up to 32GB.

A kind of clarifcation (all 64GB or 128GB must be accessible if formatted as FAT32) -- https://android.stackexchange.com/a/155396/13117 by blunden:  ...as long as the user reformatted the cards as FAT32 (or another supported filesystem I imagine). The SDXC standard mandates that the cards are sold formatted as exFAT but the standard also includes backward compatibility with SDHC devices, albeit at slightly lower speeds.


text:
screen cracked android - so I cannot gesture unlock
I have a fairly common issue: a screen damaged android phone. These devices are highly vulnerable to broken screens (this particular phone, the samsung galaxy note 3, had 2 replacement screens before this one) I refuse to purchase another to simply get my data.
As I read about it I am disgusted at the attitude of the data thieves at google: (I make no bones about it, it is laughable to call it "security" - it is simply deliberate data theft in the guise of obscurity - and I know this because I write systems that do much more security for far less damage)
But forget the disgust, for the purposes of this question just ignore it, just don't try to defend it, or censor that I wrote it. I know what I am talking about.
As I say, I am a developer on Android so I already had adb installed on my pc and already had usb debugging enabled:
First I tried this: 1) Since my Google Account was set up on the phone I went to Google "remote locking" service http:www.android.com devicemanager only to discover that while this service LOCKS phones it does not UNLOCK them (...?) (x ANDROID FAIL)
Secondly I tried to : 2) use adb to adb shell rm /data/system/gesture.key but it is permission denied (x ANDROID FAIL)
Thirdly I tried to root the phone so I could use adb: 3) However even though I have now rooted the phone, I rooted it with the lock screen locked, so I cannot get the initial gesture unlock, to work to "confirm click" the root: (x ANDROID FAIL)

Fourthly I tried : 4)  the tool "Android Control.exe" http: android-control.software.informer.com/ seems to show the most promise but it only replicates gestures in on gesture vector, i.e. if your unlock gesture changes direction (as mine does) then h will not work - i.e. more than a single direction in a swipe and you have no way in: (x ANDROID FAIL)
Fifthly I learnt : 5) I could use a VNC if I had installed the server on the phone before hand (x ANDROID FAIL)
So, my question is, while locked out of my property by a bunch of slack idiots who are paid far too much, can anyone suggest a way out other than the five ridiculous android fails tried and the with I want to wait to try:
Options 6) is to buy a [micro usb hdmi/ usb mouse dongle][3] but it is a lot of money for a device that I need to use only once to swipe only once

To do 2), you must run the adb shell as root.

.. that's why it is good to read 3)

So you executed the command as root user and it still returned no permission?

no, the phone was not rooted, the screen cracked, I then rooted it but I cannot confirm the rooting ona locked phone, because to be rooted because I have to physically accept a confirm box, on the phone, which I cannot get to

quite honestly why you cannot type in a numeric representation of the bloody gesture in adb is beyond me. there are 9 positions, name them 1-9 then you're done. adb gesture-unlock 34561 would do, have a timeout exponentially on response to rule out crack attempts - done.

That's because adb's logic is not that. It simply is a tool to use command-terminal of Android to execute commands, that GUIs execute at background, manually from your PC. You can use TWRP's File Manager to delete the file you want to delete (I don't know if other Custom Recoveries have File Managers).

bit off topic, but it would be trivial to send a gesture representation via the command line to data/system/gesture.key and then wait 180 seconds the offer to remove it via "y" if it is the correct gesture

doesn't TWRP have to be installed as an app on a already rooted phone?

@MrHeelis TWRP is a recovery, not an app. You install/flash it using ODIN and simply do the three-button-boot-to-recovery combination of volume-up+home+power-on and use it. Although I think TWRP is a touch-only recovery, so I would recommend CWM or PhilZ recovery (both allow button-only use.

GiantTree this sounds like the answer can you please write that as an answer, with some links and step by step break down of what said,  so I can accept it

I've heard that Note 3 supports OTG and OTG cable are way too cheap nowadays. Can you not grab one and combined with a standard PC mouse, use it to unlock the screen or do whatever you would using one finger touch? Also, use @ to notify somebody. @GiantTree wouldn't have received your comment about requesting a formal answer.

@GiantTree AHH.. That's so true. TWRP works with touch screen. I feel really so... Does CWM have file manager?

@SarpSTA I don't know, I haven't used CWM in a while. I know PhilZ recovery has (I'm using it on my S6 Edge).

@SarpSTA, well turns out Philz does not have a built in file manager like TWRP, but an always active adb daemon in root mode, which helps far more than just a file manager.

MrHeelis You must pay attention to it. Install the Philz Custom recovery and use adb commands to remove the file. @GiantTree turned it into one really good answer.

@SarpSTA It is not mandatory though, but if you genuinely think that an answer is really good, make sure to upvote it. It gives a better signal to others that the post is helpful. Just a suggestion. :)

WARNING: Follow these instructions only, if you are aware of the risks!
I am not responsible for any hard-/soft-brick! Proceed only if you know what you are doing!
Possible loss of warranty by triggering KNOX flags, flash counters etc.!!!
READ THE ENTIRE ANSWER BEFORE FOLLOWING ANY OF THESE STEPS!!!
Install CWM and Philz recovery.
If you not already have a custom recovery installed:
Use ODIN to flash a third party recovery. I recommend PhilZ recovery, because you can navigate through all menus using only the buttons on your device:
First: Download ODIN, CWM recovery and PhilZ touch recovery from this XDA-thread: http://forum.xda-developers.com/galaxy-note-3/general/n900-one-guide-t3252033 (you may want to read that post, too).
You will need to install Philz with CWM, because CWM does not feature a file manager and Philz can only be flashed through another non-stock recovery.
Next: Shutdown your device and boot into the bootloader.
You may use adb reboot bootloader or the combination: Power + Home + Volume-DOWN
Install CWM (this will trigger any flash counter, KNOX warranty void bit etc., only proceed if there is a way to undo this or you will most certainly loose your warranty):

Unpack ODIN and launch the application.
In ODIN: Click on the PDA button and select the CWM .tar archive
Now, connect your phone to your PC and click the Start button.

You now have CWM installed!

Your phone should reboot automatically, so after it finished booting, copy the Philz recovery .zip onto your device's storage. You can use either the Windows Explorer or adb push <zip file> /sdcard/ for this. I'm not sure if the Windows Explorer method works with a locked screen, though.
Reboot into the CWM recovery by either shutting down your device and pressing the combination Power + Home + Volume-UP or using adb reboot recovery
Use your volume up/down buttons to select install zip from sdcard and confirm it by pressing the power button (it's possible to install a zip through sideload, but sideloading is not very reliable from others' and my experience)
Select your philz recovery .zip file and confirm to flash it.
Reboot the recovery by going into the Advanced menu and selecting reboot recovery
You will now be greeted by the Philz recovery screen.

Do all sorts of root commands:

Use your PC to run adb shell. You will automatically be in root mode (check whoami -> root)
Remove the .key files that prevent you from unlocking your device. (rm /data/system/gesture.key)
Reboot the device by simply selecting Reboot System Now and pressing the power button.

You should now have no screen lock, as Android is unable to find the key that is used to compare your input gesture to and will fall back to either no lock at all or swipe to unlock.
I can confirm that this guide is working with the Galaxy S6 Edge (SM-G925F), if the proper files are used.


text:
I broke my WiFi Card, Can I use my data antenna to connect to WiFi
I have an old android phone that I want to use to stream music while I am working around the house. Is it possible to make my data antenna work as a WiFi card? I am currently not rooted.
Here are the specs:
OS:Android (2.3.6, 2.3, 2.2)
Hardware
System chip:Qualcomm MSM7627-2
Processor:Single core, 600 MHz
System memory:512 MB RAM / 512 MB ROM
Storage expansion:microSD, microSDHC up to 32 GB
Technology
CDMA:800, 1900 MHz
Data:EV-DO Rev.A
Positioning:GPS
Navigation:Yes
Connectivity
Bluetooth:3.0
Wi-Fi:Yes
USB:Yes
Connector:microUSB
*Edit
I should also mention that the damage was caused by water

How do you know you broke your WiFi card?

@mattm Water damage. I forgot it in my pocket, and it went through the wash.

No, it is not possible to use your data antenna as a WiFi card. These are tuned to different frequencies, and the required processing for each is also different.


text:
Are there any downsides to using a nandroid recovery?
A nandroid backup is designed to provide a backup for an Android device.
Are there any downsides to restoring a nandroid backup (besides losing any changes since the nandroid was created)?
In other words, as an experiment, let's say you take a perfectly functioning Android device (yes, a mythical beast, but I digress...), then create a nandroid, and then immediately perform a restore from that nandroid.  After the restore is finished, are you back exactly how things were before you performed the restore?  Or are there subtle internal differences?  Any affect on root?

A nandroid backup is a full device backup – so you could ask the same question about a full backup of your PC: After restoring the backup, you'd be at exactly the state the device was in when you performed that backup – all changes done between making the backup and restoring it are lost.
Reading between the lines of your question, you're rather asking how a Nandroid backup works or what its pros and cons are. There were some changes in the past years, and I don't know to which custom recoveries they apply (I can only speak for clockworkmod for long-term and twrp for, say, the last year. So let me sum up:
In the past …

Nandroid backups were created as partition images
there was one image per partition (relevant partitions only, of course)
those image files were uncompressed 1:1 blockwise copies of the corresponding partitions

2012 example from my Motorola Milestone 2:

-r-xr-xr-x 1    8388608 Apr 29  2012 boot.img
-r-xr-xr-x 1      10560 Apr 29  2012 cache.img
-r-xr-xr-x 1  346287744 Apr 29  2012 data.img
-r--r--r-- 1        288 Apr 30  2012 local.prop
-r-xr-xr-x 1        132 Apr 29  2012 nandroid.md5
-r-xr-xr-x 1  301956864 Apr 29  2012 system.img

2010 example from my "good old" HTC Buzz:

-r-xr-xr-x 1    2883584 Okt 23  2010 boot.img
-r-xr-xr-x 1      12672 Okt 23  2010 cache.img
-r-xr-xr-x 1  112421760 Okt 23  2010 data.img
-r-xr-xr-x 1        222 Okt 23  2010 nandroid.md5
-r-xr-xr-x 1    4325376 Okt 23  2010 recovery.img
-r-xr-xr-x 1  213227520 Okt 23  2010 system.img

These two have been created by CWM. So you see, at least from 2010 to 2012 this was what Nandroid did.
As these were full disk images ("physical copies", 1:1 block-wise), restoring them of course meant all contents on the target lost and replaced by the backup, which was restored block-wise as well. Both above nandroids were created by CWM.
Nowadays …
… things are a little different:

Nandroid backups are mostly created as tarballs, i.e. logical copies of all files of a partition
There's one tarball per (relevant) partition, often with the exception of /boot which remained an image copy
those archives are uncompressed

2015 example from my LG P880, created by CWM as well:

-r-xr-xr-x 1   10485760 Mai 29 22:48 boot.img
-r-xr-xr-x 1          0 Mai 29 22:50 cache.ext4.tar
-r-xr-xr-x 1      23040 Mai 29 22:50 cache.ext4.tar.a
-r-xr-xr-x 1          0 Mai 29 22:49 data.ext4.tar
-r-xr-xr-x 1  650801664 Mai 29 22:50 data.ext4.tar.a
-r-xr-xr-x 1        390 Mai 29 22:52 nandroid.md5
-r-xr-xr-x 1   10485760 Mai 29 22:48 recovery.img
-r-xr-xr-x 1     136590 Mai 29 22:52 recovery.log
-r-xr-xr-x 1          0 Mai 29 22:48 system.ext4.tar
-r-xr-xr-x 1  947858944 Mai 29 22:49 system.ext4.tar.a

2015 example from my Motorola Milestone 2, this time done with TWRP:

-r--r--r-- 1  247035904 Sep  6 23:14 data.ext3.win
-r--r--r-- 1         48 Sep  6 23:14 data.ext3.win.md5
-r--r--r-- 1        104 Sep  6 23:39 _original_dir_name
-r--r--r-- 1     184842 Sep  6 23:14 recovery.log
-r--r--r-- 1  287747072 Sep  6 23:15 system.ext3.win
-r--r--r-- 1         50 Sep  6 23:14 system.ext3.win.md5

In both cases, we now have .tar files for normal partitions (don't ask me why TWRP names them .win), and disk images for /boot and /recovery. Note that TWRP forgot to backup these two partitions; I'd count that a bug, but specific to the build used here (I didn't decide to switch to TWRP, it simply came with the CyanogenMod ROM).
Other notes
The original "physical copies" (aka "disk images") had a big advantage: if you accidentally deleted something from your device, you could use file-carving technologies on the Nandroid images to get it back (see our data-recovery tag-wiki). This no longer works with tarballs. But tarballs can be restored even after partition resizing – while restoring an image file results in the same partition size (and fails if e.g. the partition got smaller). Also, switching to tar made the backups somehow "independent" from the file system – so you could back-up ext3 and restore to ext4 without having the partition put back to ext3.
On the other hand, there's one thing which got easier with tarballs: Looking inside them to retrieve a file or easily evaluate the structure on your PC. Not that I'd count this as a "big pro": with the correct tools (here: TestDisk) one can do the very same with images. It just takes a little longer, as TestDisk needs to investigate the structure (partition type, file system) before contents can be accessed.
As for restore, there should be almost no difference from the "users experience with results":

restoring an image overwrites the entire partition, restoring each block as it was before (including "bad blocks")
just unpacking a tarball wouldn't overwrite "new files", so this could result in a mess; I'm confident Nandroid takes care for this by wiping the target partition first
another minimal pro of the tarballs: restoring such a Nandroid implicitly includes a "defrag", with files being written sequentially and without any delete in between ;)

My personal opinion is: Nandroids are backups. Backups are meant to be restored from in cases of emergency. Thus, while the Tar archieves have their conveniences, disk images are preferable – as one can use file-carving to even restore deleted stuff. But pros and cons are rather subjective.
Verdict
Though there might be "subtle differences" (as e.g. the now "defrag'd" partitions if your Nandroid used tarballs), there are no differences the "normal user" should notice. As Nandroid backups always include the entire partition, everything gets backed up and such restored – including "root and his files".

+1. Yes, this is one of the kind of answers that made me attract and contribute to this site. Anyhow, I was bit lost at "disk images are preferable – as one can use file-carving to even restore deleted stuff" but later realized that since disk imaging is at block level, it would copy all blocks regardless of whether the filesystem logically shows any data to the user. So if our reader ended up accidentally deleting something, they could have taken an image of the partition (which includes blocks with deleted data as well) and ran some file recovery software.

Exactly that, @Firelord – thanks for making it clearer! Yes, by "file-carving technologies" I referred to "some file recovery software" such as Scalpel or TestDisk :)


text:
Android updates availability in different countries
I am Indian and I just moved in to UK. I have seen some good deals on a mobile and I would like to buy it. But I'm worried if I would get software updates for the mobile that purchased when I reach my country back.I tried googling but I couldn't get hold of anything useful. Please clarify.

Well, software updates depend on different things:

the manufacturer (if they actually release any updates)
the carrier (unless you get the international version)
your internet connection (no internet = no updates)

You get the updates from the country where you bought the device from (unless you flash a different one, check on the CSC: Carrier/Country Specific Code).
Note that you might need to make at least a 5 minute call using a SIM originating from the buying location to unlock usage of international carriers' SIM cards. Also make sure all the needed bands for connecting to the network of your carrier (most phones support all bands, so no real problem there).
All these note are also printed on the package, in the user manual or both.


text:
Do I lose my data if i factory reset my phone?
If I factory reset my phone, how long will it take for my data to set itself back up? And if it doesn't, have I lost my data?

Factory reset will wipe everything in your device and your device will be as when you bought it. You should always backup your data before factory reset if you need it for after use.

And your data doesn't "set itself back up" again after that. That's something you have to take care for yourself. Even not if you've enabled Google's cloud backup – which at least up to Android 5.x includes parts at best.

Your data does not set itself back up, factory resets remove everything on the phone memory so you should back up your data before you do a factory reset then copy it back to the phone after the reset is completed.


text:
Black status bar icon on Marshmallow making it unreadable on dark wallpaper
Even though the title enunciates the problem, the question is about a solution or workaround to this behaviour.
As I have found, Marshmallow normally colors the status bar icons (Wi-Fi, Battery, Clock) on the launcher (home screens) by taking the colour of the topmost region of the wallpaper currently set and tinting the icons to a darker version of it.
This is all well and good if you have the sky there in your wallpaper, or something light-coloured; but if you have a night-time cityscape as your wallpaper, it colours the icons to be "Darker Than Black" (pun intended). So, magically, your Wi-Fi, Battery, Clock and everything else just disappears from the status bar. Only they haven't disappeared. Set a light wallpaper or a dark one with the top region light, and they're back.
I don't think that this is a problem with the launcher, as I use both Nova Prime and Google Now Launcher, and both have this problem. I also checked the System UI Tuner options for such settings relating to this tinting mechanism, and they're nonexistent (The settings there include what statusbar icons and quick settings tiles to show, battery icon customization, demo mode, and that's it).
I know of 3 possible workarounds to prevent this behaviour:

Disable Nova Launcher's transparent statusbar option under "Look and Feel", but I don't want to do that.
Use Xposed+FSCB (Flat Style Colored Bars) or similar. Well, Xposed on Lollipop 32-bit was unstable. Marshmallow ARM64? (I really have no idea, but I'm definitely not willing to take the risk.
This was a no-brainer. Use a light wallpaper. (Well, then I wouldn't have asked this question, would I?)

The question is: "Can I have the best of both worlds (i.e., my dark nighttime cityscapes as wallpapers and visible statusbar icons)?"
The solutions I'll prefer can involve root but not Xposed, and not 1 or 3 above. Also, it's preferable if the solution tints the icons to white on a dark wallpaper but preserves the stock behaviour otherwise, and doesn't affect apps other than the launcher, because my problem doesn't affect apps other than the launcher.
Background:
My HTC Nexus 9 16GB, Wi-Fi, flounder/volantis running Marshmallow 6.0.0 MRA58K rooted with TWRP 2.8.7.0 ElementalX 4.02
Some pictures:
Click images to enlarge
Light wallpaper:

Dark wallpaper:

Dark wallpaper with light top region (Whaat?):

What I want ( This is from my phone, same Nova Prime, 4.4.2, (Lollipop signal icons courtesy GravityBox KK)):

@AndrewT. I don't know why it was happening in Google Now Launcher, but turning off said feature in Nova fixed the issue in both launchers

I had no idea Nova enabled this by default on Marshmallow. The option doesn't seem to exist on my 4.4.2 phone

Yeah, that problem might be on my side, but as it got solved, I won't investigate it further. Thanks.

Based on reddit (and I have tested it myself), apparently it's a feature of Nova Launcher on Android 6.0 Marshmallow called "Dark icons". It seems it's enabled by default for existing users after updating the app (on my case, new installation will have to turn this setting on manually).
The setting can be checked on Nova Settings - Look & feel - Dark icons. Note that this is a new feature of Marshmallow, allowing an app to have black status icons for light status bar, and thus, the setting is only available on Marshmallow and above.
As for why it also affected Google Now Launcher, I actually have no idea, since I couldn't reproduce the issue on Nexus 5 running Marshmallow 6.0. Even if I leave the option enabled on Nova Launcher, changing the home setting (on Settings - Home - Google Now Launcher) and pressing "Home" button will revert the whole launcher to Google Now Launcher with its default white icon.

You're right. I got it by default by updating the app.

I can't believe that I've just changed ROMs and had the same issue and couldn't work it out until I switched back to the stock launcher and found i could see the icons. Then I realized it was Nova launcher causing the issue. Thanks I've now solved the problem.

Based on @Andrew T.'s research, I understood that this isn't actually an issue with the system, rather it was a feature, "Dark Icons", that Nova Launcher only shows on and enables by default on Marshmallow, not on KitKat or lower (unsure about Lollipop).
The option on Marshmallow devices exists under Nova Settings → Look and Feel → Dark Icons (a switch). Disabling this made the icons go white everywhere, as normal.
I had no idea why this affected Google Now Launcher also, but disabling the option in Nova fixed it there too. The effect on Google Now Launcher made me think it was a system feature/bug, but I'll clarify this was not actually so. This was due to Nova Launcher and some unknown condition which made it affect both launchers. That reason might be system-specific. Thanks for everyone's help.


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Rumour About cyanogen mod
Some of my friends have been saying that Cyanogen os is inferior to Oxygen os as three former is not 'upgradable' any more but the latter is.I don't know how much is true and what is true. Will anyone help me get things clarified?

It appears that your friends do not understand what they say, perhaps are not updated with latest info, or maybe you gave us partial info. Whatever the case maybe, see the official info: Marshmallow upgrade schedule for OnePlus devices.

Both Cyanogen OS and Oxygen OS are skins layered on top of Android. For years, manufacturers of smartphones have put their own software on their phones in order to set their phone apart. Every skin has its pros and cons: OxygenOS  bundles various apps like Swiftkey and MaxxAudio, Cyanogen OS bundles different sofware, like AudioFX and Privacy Guard.
I recommend you compare the two roms carefully, but there is no objective winner in my eyes.

I wanted to know more specifically about the upgrades issue.

Asserting you are talking about the OnePlus One, something happened between OnePlus and Cyanogen, causing OnePlus to develop OxygenOS. I have no clue which skins are still supported by OnePlus since I do not own one, but if OnePlus or Cyanogen Inc. dropped support of one of them, you are wiser to switch to the other one. At this point, I'd recommend doing some research yourself to see which rom is better supported: I'd look at public statements made by the author, release frequency and release date of initial version.


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Certificate Authority installation doesn't work
I've seen many many posts* lined to my problem, although none of them seems to refer to my bug.
I set up my small PKI (for Web, mail etc.) and now try to import my CA .crt file to my Android device. Each time I try to open the cert file I am prompted for entering a name for the imported CA. I then validate the name and the purpose (VPN and applications) and a small Pop-up appears "MyCA has been imported."
However, when I go to Preferences > Security > Trusted certificates > User certificates, my CA doesn't appear.
I tried to download it :

via Web (URL pointing directly to the .crt file encoded in PEM)
with the file (uploaded to Downloads/ folder, then Import from SD > Internal, same behavior)
via ADB to the added-certs/ folder (access restrictions indeed)

Does someone have an idea ?
My phone :
Android 5.1.1
OxygenOS 2.1.2
OnePlus X
Thanks !
*Unable to Install Certificate
*How do I install a user certificate?
*http://androidforums.com/threads/cant-install-security-certificate.668968/
*How do you import CA certificates onto an Android phone?

OnePlus ticket : #494797


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Storage cannot be found from apps, folder /storage/emulated missing
I installed a custom ROM (CM 12.1, based on Android 5.1.1) on my Galaxy S2 (GT-I9100). Also, I repartitioned the storage using this PIT file: I9100_2.0GB_Sys-05GB_Data-023MB_Preload.
All but the access to the memory (internal and external storage) works fine. Unfortunately it is not possible to write or detect both storage points. The consequence is that apps like the camera, or downloading any content do not work. If I remove the SD card from slot most of these app crashes or display an error message.
However, the SD card is not damaged. I already used it for installing the ROM and it is detected inside the file manager (/storage/sdcard1). Inside the file manager I can create or delete files and folders, too.
The problem seems to be a missing mount point that links to the internal storage. Comparing this device with another device with CM the following folders are missing:

/storage/emulated
/storage/emulated/0
/storage/emulated/legacy

These folders are empty (it should contain a folder Android):

/sdcard
/storage/sdcard0
/mnt/sdcard

The folders and mount points for the external storage (SD card) exist but apps (except the file browser) cannot use them. These are folders that seems to be correct:

/extSdCard
/storage/sdcard1

In my opinion a shortcut to internal storage ist wrong or missing. Do you have any idea how I can fix the issue? Thanks a lot.

Seems that your repartitioned storage doesn't mount correctly, for some reason, perhaps due to partitioning error. Maybe try repartitioning it again? Or, if you're into some android-hacking, try to check it out trough adb to see if it's possible to mount any of those partitions and what errors might show up, that could give a clue of wgat's wrong. Or, check it out with adb, if you can mount those partitions, and what errors show up if you can't, that'll give a clue of what's wrong.

I already mounted from recovery. There came no error. But the mount points are removed at start. Is it possible that the used Pit file forgot defining the internal app storage?

1.take a look at /etc/vold.fstab, if there is such a file (rom-dependant). 2.problem might be in the init.rc script, but it gets more complicated. More details on how to get to the insides of the init.rc here -> http://stackoverflow.com/a/11807215    Let me know if anything of this is helpful.

The FS wouldn't mount from properly if it was corrupted. By the way, did you try flashing another ROM?

I have not tried another ROM yet. The file /etc/vold.fstab does not exist. File /init.rc exists. Thanks for the link, I will have a look into.


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where are my downloaded google play apps? i cannot find them in apps on my surface
I have downloaded several apps from google play on my surface but they are no where to be found. I have tried search and poked around download files but nothing. Should it really be this hard? Seems ridiculous.

Did you even search online about your question or even here before posting the question? Please demonstrate that you have put in some effort to researching a solution or at least tell us what you have done, that helps us to provide more relevant answers.

Maybe, next time :)

Google Play doesn't download .apk files to your phone but install the application. If you want to find the base.apk though you can find it in:
/data/app/app.package.name
however, it is off-limits to a non-root user. Your stock File Manager app won't let you browse that partition and third party browsers will return Access Denied when try to reach /data partition as non-root.

Yep, but there is still hope. adb pull /data/app/PACKAGE or any backup app in Play Store would do. :)

And it's /data/app/<package_name>.apk IIRC :) Exact name and location can be obtained using adb shell "dumpsys package" | egrep -A99999 "Package \[<package_name_here>\]" and check the first line containing the keyword codePath :)

@Izzy and adb shell pm path PACKAGE would be a shortcut too. :) Perhaps, adb shell "dumpsys package PACKAGE" | egrep "codePath=". Of course, who am I kidding with?

Many roads lead to Rome :) But your last command would dump all .apk files. The first one however is better than my "quick check", @Firelord ;)

Ah, sorry. I've tried that, and got nothing back. Turns out I've had a typo in the package name #/ OK, so forget that: both work, but the first is easier :)

@Izzy And we both forgot the easiest one we suggest to others, adb shell pm list packages -f PACKAGE. :)

@Firelord It sounded like OP wanted to find the .apk within the phone and that's why I suggested in-device methods. Neither adb nor backup apps wouldn't work without root as well anyway.

ADB and those backup apps can fetch the APK with no problem. No root is required for that. :) Try it! That's why I wrote "there is still hope".

@Firelord It does? How though? Isn't both the backup app and ADB shell are just users? Shouldn't their demand to access another users data be denied?

@SarpSTA especially for backup purposes, ADB got elevated privileges (starting with ICS). "General info" is also considered "safe enough", as in order to use ADB the user must authorize it (at least once) on the device itself, which requires unlocking the screen. So that command sees nothing a normal user app could not obtain.

Because this answer does the job nicely, so I need not to explain anything here. Make sure you upvote this: Get APK of installed app

@Firelord It is only for /data/app right? Not /data/data. That'd be pretty unsafe.


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Why are all my websites suddenly loaded in desktop mode?
A little while ago my YouTube wasn't working on Chrome on Android tablets, so I hit "Request desktop" and the videos were working fine. But about a month later, Chrome started loading all of my websites in desktop mode, even the search results.
I want all my sites to load in mobile except for YouTube. I don't know why it started happening and I have no idea how to fix it. Please help!

It's okay if you don't have an idea at first. It's a common occurrence among others as well. But in that case, you should always go to Uncle Web and see if he can help you with that. He's very kind and he always helps.

If you are using Chrome, tap on the right side menu icon and uncheck Request Desktop Site.


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stuck on bootloop due to installed xposed framework
i recently installed xposed framework on my X-TIGI A5 china smartphone and on restart got into a bootloop,i have tried on the custom recovery but it seems that my device does not have either twrp or cwmr..anyone help me restore my device??

If you haven't installed them then of course your phone won't have TWRP or CWM.

You could try formatting your phone in stock recovery even if you don't have any custom recovery such as TWRP or CWM installed.

This won't work. Xposed is installed on /system which is left unaffected by a factory reset.

How did he gain root access without a custom recovery ?

@user2119, search 1-click root access on web.

Hmm intrestting ; well I use a galaxy,so I installed a custom recovery using Odin and then only rooted my phone


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How to start a bootlooping phone in Safe Mode
Exactly a week today, I updated Podcast Addict on my Alcatel One Touch M'pop 5020D. It shut down immediately I opened it. And then other apps started shutting down too. So before going to bed I restarted the cell. I woke up at dawn to realize it was stuck in bootloop.
I've tried wiping the cache partition and performing a factory reset in Recovery Mode, but that hasn't helped. Fortunately or unfortunately (I'm currently in a state of confusion as to whether or not this was a good decision after all) my phone is not rooted. I therefore can not apply several options in fixing this. I'd like to know if there's any way, any medium at all, that I can boot into Safe Mode so I can uninstall the Podcast Addict. Thanks for the help.

If you have a working ADB bridge in your recovery you can uninstall the app, more information can be found here.

Sorry for the disappointing news, but there is no way to boot into safe mode without USB debugging enabled and already authorized by Android, and  root access or a custom recovery.
The content of the file named persist.sys.safemode must be set to 1 for the device to boot into safe mode. The file is located under /data/property, is  owned by root user and is part of root group only. If only the root privileges are granted, the file can be edited.


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How to turn off Radio Signal via adb without airplane mode?
As I'm trying to make a script to restart radio signal and I'm not using usb cable for adb, I need to turn off my mobile signal WITHOUT using airplane (because I'm using Wifi Hotspot and Wifi ADB).
Is there a solution for that?
I have root and wifi adb running smoothly... and I have seen some solution as disabling mobile data and so on but this is not enough for me. My carrier sometimes stop providing me mobile connection and the only way to get active mobile data is to restart the radio signal (just as I'd do if I type ##4636*#*# and press the "turn off/on radio" button).
Also if possible, after turning off radio signal, I'd need to wait +- 10 seconds before going on again (I suppose the command for that is sleep 10).
Thanks :D
PS: Android Lollipop 5.1.1 (Xperia Z1)

I need to turn off my mobile signal WITHOUT using airplane (because I'm using Wifi Hotspot and Wifi ADB).

You can configure your device to not stop  Wi-Fi (Hotspot includes) when activating Airplane mode.
(Note: I tested the solution in Android 4.2.1, 4.4.2, 5.0.2 and 5.1.1.)
The radios that are supposed to be turned off when Airplane mode gets enabled are saved  in the key airplane_mode_radios under the table global inside /data/data/com.android.settings/databases/settings.db (Settings Storage app's database).
Set up adb in PC, enable USB debugging in device, connect it into PC, launch a shell and enter either one of the command
adb shell settings get global airplane_mode_radios
adb shell content query --uri content://settings/global  --projection name:value --where "name='airplane_mode_radios'"

(See usage of settings and content command using adb shell settings and adb shell content)
Given the command you executed you would see something like (either one of the result):
cell,bluetooth,wifi,nfc,wimax
Row: 0 name=airplane_mode_radios, value=cell,bluetooth,wifi,nfc,wimax

You can choose to remove wifi from the value to achieve the final objective.
Enter any one of the commands:
adb shell settings put global airplane_mode_radios  "cell,bluetooth,nfc,wimax"
adb shell content update --uri content://settings/global --bind value:s:'cell,bluetooth,nfc,wimax' --where "name='airplane_mode_radios'"

Note: Do not copy-paste. Note the string that you got in the first output. Then remove wifi, from it and then pass the resultant between the double quotes "" the way I've shown above.
Now you can turn on the Wi-Fi/Hotspot followed by the Airplane mode. Your Wi-Fi/Hotspot wouldn't turn off.
The need for using ADB was meant for once only.  If you decide to stop Wi-Fi when Airplane mode becomes active then simply add  wifi in that key's value.
Answer originally written for Possible to turn on Airplane mode with WiFi on only?

Thanks! In addition to that, for Airplane On and Off function, I followed this How to turn off cellular radio in Lollipop/JellyBean using adb? only adding ADB SHEEL before each command. :D

Ah, that's what I'd needed a week ago. If you just update the fields in the database, it only gets activated after a reboot. I bet yours dosn't need that :)


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nexus 5 shared internet connection
I try to share my internet connection from my nexus 5 to my computer (on ubuntu).
So I enabled wifi hotspot on my phone bu following http://www.gottabemobile.com/2014/01/25/how-to-use-the-nexus-5-as-a-personal-hotspot/ but it doenst work.
The connection between my computer and my phone is working but when I tried to connect to google the connection fail.
I installed tcpdump (by cross-compiling it) and I can see the SYN packet(but there is no SYN ACK) on the wlan0 interface but not on rmnet0(which is the interface where is my internet connection) so I guess it is a routing problem.
routing is enabled:
root@hammerhead:/ # cat /proc/sys/net/ipv4/ip_forward
1

the interfaces :
root@hammerhead:/ # ip link | grep UP
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN mode DEFAULT
2: rmnet0: <UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN mode DEFAULT qlen 1000
21: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000

the route table:
10.8.91.76/30 dev rmnet0  proto kernel  scope link  src 10.8.91.77
172.20.2.10 via 10.8.91.78 dev rmnet0  src 10.8.91.77
172.20.2.39 via 10.8.91.78 dev rmnet0  src 10.8.91.77
192.168.43.0/24 dev wlan0  proto kernel  scope link  src 192.168.43.1

root@hammerhead:/ # ip route
A.A.A.B/30 dev rmnet0  proto kernel  scope link  src A
172.20.2.10 via 10.8.91.78 dev rmnet0  src 10.8.91.77
172.20.2.39 via 10.8.91.78 dev rmnet0  src 10.8.91.77
192.168.43.0/24 dev wlan0  proto kernel  scope link  src 192.168.43.1

the firewall :
root@hammerhead:/ # iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
bw_INPUT   all  --  anywhere             anywhere
fw_INPUT   all  --  anywhere             anywhere

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
oem_fwd    all  --  anywhere             anywhere
fw_FORWARD  all  --  anywhere             anywhere
bw_FORWARD  all  --  anywhere             anywhere
natctrl_FORWARD  all  --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
oem_out    all  --  anywhere             anywhere
fw_OUTPUT  all  --  anywhere             anywhere
bw_OUTPUT  all  --  anywhere             anywhere

Chain bw_FORWARD (1 references)
target     prot opt source               destination

Chain bw_INPUT (1 references)
target     prot opt source               destination
           all  --  anywhere             anywhere             ! quota globalAlert: 2097152 bytes
bw_costly_rmnet0  all  --  anywhere             anywhere
           all  --  anywhere             anywhere             owner socket exists

Chain bw_OUTPUT (1 references)
target     prot opt source               destination
           all  --  anywhere             anywhere             ! quota globalAlert: 2097152 bytes
bw_costly_rmnet0  all  --  anywhere             anywhere
           all  --  anywhere             anywhere             owner socket exists

Chain bw_costly_rmnet0 (2 references)
target     prot opt source               destination
bw_penalty_box  all  --  anywhere             anywhere
REJECT     all  --  anywhere             anywhere             ! quota rmnet0: 9223372036854775807 bytes  reject-with icmp-port-unreachable

Chain bw_costly_shared (0 references)
target     prot opt source               destination
bw_penalty_box  all  --  anywhere             anywhere

Chain bw_happy_box (0 references)
target     prot opt source               destination

Chain bw_penalty_box (2 references)
target     prot opt source               destination
REJECT     all  --  anywhere             anywhere             owner UID match u0_a14 reject-with icmp-port-unreachable

Chain fw_FORWARD (1 references)
target     prot opt source               destination

Chain fw_INPUT (1 references)
target     prot opt source               destination

Chain fw_OUTPUT (1 references)
target     prot opt source               destination

Chain natctrl_FORWARD (1 references)
target     prot opt source               destination
DROP       all  --  anywhere             anywhere

Chain natctrl_tether_counters (0 references)
target     prot opt source               destination

Chain oem_fwd (1 references)
target     prot opt source               destination

Chain oem_out (1 references)
target     prot opt source               destination

do you know why it doens't work.
Also when i do ping 8.8.8.8 from my phone all is working but i don't understand why : there is no default route so how can it decide where to go? can you explain?
thank you

Thank your for your answer but it doesn't work.
`# route add default gw 8.8.8.8 dev rmnet0` give me `Network is unreachable`

oh yes of course sorry. I executed route add default gw 8.8.8.8 dev wlan0 (wlan0 of the computer) but i have the same error which is quite logical. I think there is no problem on the configuration of the computer because when I try telnet 8.8.8.8 53 the SYN packet can be read from the wlan0 interface of the phone. The problem is it doesn't go to the rmnet0 (it seems it is not forwarded).

Do you have tethering on your cell plan? Otherwise, the built-in hotspot probably won't work.

(Also, to understand routing on the phone you'll have to look at ip rule; there is more than one routing table. ip route list table X to look at a different one, where X is a table number which you'll see in the ip rule output. Look up Linux policy routing for an explanation.)


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Tablet doesn't respond to touch neither when mouse is plugged in, at all
Recently my Colorfly E708 Q2 tablet stopped working. First time this happened a message box popped up, with the text "Unfortunately System UI has stopped" or something like that, but i wasn't able to close the pop-up box, because the system didn't respond to any user interaction. So i decided to restart the tablet.
Display doesn't work, doesn't respond to touch, nor to mouse when connected through usb. I need to mention, that when the mouse is connected, the mouse cursor shows up on the screen, and does even track the movements of the mouse, but as i said, it does not respond to clicks.
I've seen on some forums, that the only thing that would help to fix the tablet would be if i'd replace the firmware. Sadly, since the developer options aren't enabled on the tablet, i was not able to reboot into a boot menu. The device has no physical sound buttons (only power, home and reset) , so what would work with other devices, doesn't work in my case.
Is there any way to fix the system ui, or re-flash it in any way? I mean it was cheap, but it worked for me so I don't really want to buy a new one.
UPDATE:
I plugged in an USB keyboard, but the only thing I could achieve was to adjust the volume of the device.
+ A new box popped up, with the message "Launcher stopped working", with two actions: wait and close. Of course its not possible to select either.
Documents:
Tech Specs
User Manual

Max, just to confirm: have you attempted to use Power and Home button in combination when phone is powered off?

@Firelord i did. i tried but until  i don't release one or the other, the tablet wont start. it just hangs there with a black screen. I have tried all the 6 possible combinations with the buttons, and then some patterns. Non worked so far

Max, I don't have a tablet or the Android KitKat but in Lollipop I am perfectly able to enable debugging mode using physical keyboard only. Are you claiming that navigation keys (left,right,up,down) combined with Tab key are not working? I used them to navigate. I'm also able to navigate system using num keys, mainly 2,4,8,6,5 (num lock off).

@Firelord The problem is, that the whole launcher screen is not responding. After I start the tablet, I'm able to do some general things, but i can't get the launcher to respond. The software keys aren't responding either, so the only thing i'm able to do is adjust the sound/brightness and move the mouse when plugged in.

the tablet doesn't factory reset when pressed the reset button ? usually reset button need some sort of pin (needle - don't know what they are called )

@lord-ralf-adolf i have tried that, its also mentioned in the user manual, but it does not change anything sadly.

NOTE: THIS WILL FACTORY RESET YOUR DEVICE!
To fix this problem, first shut down your tablet. Boot into the bootloader by booting up regularly, but holding down your power and volume up buttons when you see the logo.
If you haven't installed fastboot, do that first.Then, go to the command line and type in

fastboot oem unlock

Then, find and download a factory image, then run

fastboot flash /path/to/factory/image.zip
fastboot oem lock
fastboot reboot

Hope this helps!

I agree with attempting a factory reset, but what you are suggesting will also void the device warranty, and that needs to be clear. In addition, the question states that the user cannot navigate to the debugging options, which makes it impossible to install fastboot.

Your answer doesn't help. OP mentioned: "The device has no physical sound buttons (only power, home and reset) , so what would work with other devices, doesn't work in my case.". OP wants to either re-flash the system or enable USB debugging somehow. OP cannot achieve latter because system is not receiving touch input and cannot go for former because traditional methods of booting into recovery or bootloader doesn't apply on his tablet. Also, how are you so certain that fastboot flashing would work on his tablet? Please explain.

On page 6 of your user manual, the manufacturer suggests a reset by performing the following:
When the tablet cannot be turned on or does not respond, use a pen or another tool to poke the Resetbutton (next to the home button) and then press the Power button.
Have you tried this?

I did. nothing changed

Actually, Ethan Z, fastboot does not require usb debugging, only adb


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Make the photos taken by Android Camera app and Google Camera app smaller when created?
The photos taken by either Android Camera app or Google Camera app are too large when created. Is it possible to change some settings in the two apps to make the photos  smaller when created? Thanks.

For the Google Camera app:

Drag from the left screen edge to show the menu
Select the settings "gear" icon in the lower right
Select "resolution & quality"
Select which camera you want to change the resolution and select a smaller size

Thanks. Can you suggest what resolution is good yet not too large for what case?


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How to connect a Nexus 6p to Windows 8.1 in MTP mode
When I connect my phone to my Windows 8.1 PC, I can select PTP mode on the phone and the phone immediately shows up under "This PC".  However, I only see pictures related files, I wanted to see other media.  So I try to select MTP on my phone, and as soon as I do the phone icon disappears from "This PC" and does not reappear.  I don't see any error messages, prompts to install drivers, etc.
I read somewhere that in Android, under settings -> storage to press the menu-button and choose usb-connection, but the menu only shows "Help & feedback".
I have tried both with USB debugging enabled and disabled.
On my Windows PC, under Device Manager -> Android Device I see "Google Nexus ADB Interface"; trying to update it says the latest version is already installed.  I tried uninstalling it, and reconnecting the phone, but this just automatically reinstalled the same driver.   I also looked under every other entry in device manager and there isn't anything else related to ADB or MTP.
I don't see any kind of separate MTP driver though.  If I try to update software manually and how compatible hardware, it shows: "Google Nexus ADB Interface"  and "USB Composite Device" and nothing MTP related.
I found my device under "Devices and Printers -> Unspecified". When I tried to troubleshoot, it says "Google Nexus ADB Interface is an older USB device and might not work with USB 3.0.  Plug the device into an available USB 2.0 port..."    But I've only got USB 3.0 ports!  If I go ahead and have it finish the troubleshooting it says:
Problems found:
Google Nexus ADB Interface can't work properly with USB 3.0 (Not fixed)

What?!  The fact that PTP does work seems to contradict this, right?  And since when has USB 3.0 not been backwardly compatible with USB 2.0 devices???
How do I get my PC to recognize the phone in MTP mode?

When you plug in the device you should see in the notification shade something that says USB for Charging : Touch for more options.
If you tap that, you will have a dialog open with the following:
Use USB for

Charging
Just charge this device
Power supply
Charge the other connected device
File transfers
Transfer files to Windows or Mac (MTP)
Photo transfer (PTP)
Transfer photos or files if MTP is not supported (PTP)
MIDI
Use device for MIDI input

You want to select File transfers to have Windows detect the device as an external media device.

This is what I've done, and this is when the device disappears from Windows.


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How to change lock screen due to VPN settings
I just faced this problem.. i turned on my VPN last night and a pop up told me to change my lockscreen settings to either password or fingerprint (I'm using Samsung Galaxy Note 4), so i did. Ever since that, I cant change my lock screen settings back to none.. i have tried deleting all my VPN. I have tried to choose the Clear Credentials option but its grayed out. I have tried entering my google account at the forgot password section on the lockscreen but it shows that i had entered incorrect username or password (but I'm sure of my google account email and password). So what else can i do?

did you try your google login at a different machine? just to make sure you're not hacked. Also see http://android.stackexchange.com/questions/22867/connecting-to-vpn-forces-having-secure-screen-lock?rq=1

Are you using Android for Work? Try this:

Go to Settings > Security > Device administrators
Deactivate the entry that has installed security policies
Now go back and see if you can change your screen lock settings


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I lost my option to use a key that allows me to speak my text or emails
I have a samsung galaxy s5 - my email and text keyboard has dropped the key that allows me to speak my text and I can't find a way to get it back.

I don't have access to a Galaxy S5, but one possibility is that you have somehow disabled the voice input method, typically Google voice typing is provided as the default.
Try going to Settings > Language & input, and check whether the Google voice typing input method is disabled and if it is, enable it and try again.


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Which charging cable should I use? Short or long, and why?
I have a 7" Android RCA VoyagerII tablet.  The instructions say I must use the very short cord charger that came with it and not even try anything else.  Is this true or can I use a regular long corded phone wall charger that matches the connector?

Why the OEM is advising you is to use the charging cable that was supplied since

Shorter cables are normally thicker and offer less resistance
Impedance of the cable is matched to the charger

On the other hand, longer cables are generally thinner and offer more resistance for charging current and takes longer to charge, besides the  impedance mis-match at phone and charger ends for charging to happen as rated.
You can measure the current output of OEM cable using apps like Ampere and 3C Battery Monitoring Widget
Do stick with OEM recommendations, unless you find a long cable that matches same performance as cable supplied.
Edit: For a detailed explanation which answers "why short cables are better and how to select a USB cable", see my answer How to choose micro USB cable for my device?. I believe that would fully equip you in making a right choice

Generally a good cable to go with is a 24/28awg rated Micro Usb. I have had very good success with these on a variety of devices.


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Local media players won't play audio on movies
I have a generic Android set top box. It works fine mostly, except it won't play audio for .avi, .mkv, mp4, etc. files. I can successfully hear audio on movies via NetFlix and YouTube, but if I download a movie, there's no audio.
I have tried multiple media players, including MX Player and VLC but neither works.
I haven't knowingly changed something to cause this. Any ideas what it could be?

how is the audio encoded? Like AC3 or DTS? May be a codec problem.

Android, MX Player, VLC do not have full codec compatibility due to licensing problems. I think the audio on your movies is an ac3 or dts codec which is a 5.1 audio system, so it doesn't play natively on Android because Android uses 2.0 stereo. As I said, it can't be played natively, but there is a codec for MX Player that can play such audio formats. Follow those steps :

Go to this thread on XDA
Download the codec that matches your device's processor type (if you don't know which one to choose, search for an app called Phone Info on the Play Store. It will give you your device's type. Download the right codec)
Put the downloaded zip somewhere on your device. Example: /sdcard/download/codec_arm_V7_neon
Open MX Player and go to Setting > Decoder. Scroll all the way down and click Custom Codec, navigate to the downloaded zip location, and choose it
You may be asked to close and then reopen the MX Player, do so
You are good to go. Now your device can read AC3 and DTS sound format

I should note that the audio used to work on this device for the same files.

Are you sure it's the same file ? Because even if the extention is the same the codec might be different

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


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How do I set Google Photos to ignore videos?
I only want to back up photos and not videos.

How is this question even remotely worthy of a downvote? It's a valid question. Videos use up your storage space, whereas photos don't.

Well, it could have been more descriptive for one. Also, it did not show what you had tried already. Both are prerequisites for a question here.

In the official Google Photos app, you can't disable backup of videos per se, but you can exclude folders having videos from being backed up. That can be done like this:

In the "Device Storage" view (accessible from the swipe-in sidebar), look for the "cloud" icon to the right of the folder name.
If the Cloud icon is blue with an up arrow on it, backup of that folder is enabled. Tap on the icon to disable backup for that folder.
The Cloud icon should now become white with a slash through it. Congratulations! Backup of a folder has been disabled successfully.
It might happen that your videos are intermixed with your photos, especially if they have been shot on your camera. Move the videos to a separate folder using a file manager app, usually "Videos", and disable backup for that folder from the "Device Storage" view.

This will disable Google Auto-Backup for the selected folders only, leaving the rest unaffected.
Click on image to enlarge
Image Credits @ mobilesiri.com


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Factory reset on merged storage - Shall I lose my data
As we know, merged storage (that is, an internal SD card partition emulated by FUSE in the data partition (/data/media/0 → /storage/emulated/0) is a common thing to be found on recent devices running Kitkat and higher. Now, since this is my internal storage and contains all app and non-app data, will doing a factory reset be true to its name and wipe all of /cache and /data, including /data/media? Or, will it be considerate and keep the things under /data/media?
Note: I am asking this question to clarify a doubt and because I am not willing to do a factory reset to check this on my Nexus 9, which is the only device I have which has merged storage; but note that I asked this question for all devices with merged storage in general, which implies most stock devices with stock Android recovery on Android 4.4 and up. Please do not take the question just in context of Nexus devices. To prevent the question from being considered too broad, here are the constraints:

The device must have a standard processor (Snapdragon)
It must be AOSP stock. No OEM customized ROMs (Touchwiz, ZenUI, ColorOS) needs to be considered.
Devices are not rooted and have stock AOSP recovery.
AOSP version can be considered for 4.4.4 and 5.0 to 5.1 .
It must have merged storage.

(An answer relating to Motorola Moto devices and the Nexus 5 & 9 will be enough)
P.S. : I know that TWRP preserves /data/media while doing a wipe of /data and /cache, but I am referring here only to the stock recovery's behaviour in case of a factory reset.

@Firelord, although I mentioned my Nexus 9, my question is for all merged storage devices in general. Can someone actually confirm what "delete all user data" means? (As every device says that but the sdcard doesn't get wiped anyway)

@Firelord, The question refers to the behaviour of the stock AOSP recovery, which OEMs don't customize. Also, the question is about Android rather than specific devices. See the constraints, only Kitkat 4.4.4 and Lollipop 5.0 and 5.1 's recoveries need be considered

Thanks, @Firelord, would you consider posting your research as an answer?

According to the article  Reset your Nexus device to factory settings (Nexus 5 and Nexus 9 listed too) by Google,

By performing a factory data reset, all data will be erased from the device. While any data stored in your Google Account will be restored, all apps and their associated data will be uninstalled. Make sure you back up your data before you do a factory data reset.

The testimony of a Nexus 4 owner, coupled with supporting arguments from other Reddit users confirms that factory data reset will nuke everything.
As per AndroidPIT on How to factory reset the Nexus 5 for better performance

Since the release of Android 4.4, the ‘factory data reset’ option (accessible in the settings menu) performs the same job as a ‘hard’ reset. All of your user files, apps, etc will be deleted and your device will revert to a factory fresh state.

Their hard reset is not our hard-reset but our factory-reset using recovery mode.
Guide To Perform Hard Reset Android HTC Nexus 9 on guidebelajar blog (has useful screenshots) confirms that factory data reset for Nexus 9 would also remove every user file created or moved into the device.

As per the article How do I reset my phone? by Motorola

if you decide to factory data reset using Settings app, you would be given a choice to erase media (files under /data/media/ such as music, videos, pictures),
should you decide to boot into recovery mode, everything would be deleted

The information is also valid for Moto G (1st Gen, 2nd Gen, 3rd Gen) family of devices.
(That's all for now)


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Android keeps loosing Launch Defaults, app settings and installed updates and installed apps after every reboot
After every reboot Android keeps loosing Launch Defaults, some app settings and even some of installed updates and installed apps.
I re-flashed the stock firmware, then applied all the OTA updates. After that I only flashed TWRP, GApps (Pico Uni) and SuperSU.
Given this, I tried several Factory Resets (from Settings), but every time, after installing some number of apps, some of the above start disappearing with every reboot. As I varied the sequence of apps installed, the data lost is every time something else. Examples from different Factory Resets include:

lost default app for search on Home button tap-and-drag
lost default app for browser
lost Gmail preferences (Global ones) and/or account Sync flag
updates of Motorola Camera and Motorola Gallery (via Play Store)
some of apps I just installed (via Play Store) disappear after reboot
internal storage becomes read-only for apps (even rooted ones), but remains writable for Android File Transfer

What I tried so far:

erasing cache and dalvik cache--actually after nearly every app installed, and of course after Factory Reset
uninstalling and reinstalling every app in question
manual resetting app defaults in Settings>Apps, both globally and for individual apps
none of the apps installed to SD / internal storage, so it shouldn't be an issue

What I didn't try include:

erasing internal storage and SD card (most apps were previously "moved to SD")
whatever reformatting or repartitioning the Android partitions

Any ideas what to try next?
I have Moto G 2nd gen (XT1079 dual-SIM). It runs Android auto-updated from stock 5.0.2 22.36.1 (build LXB22.99-7.1) to stock Lollipop 5.0.2 22.46.7 (build LXB22.99-24.7).

The root cause was a wrong edition of TWRP: I mistakenly downloaded TWRP for Titan series of Moto G 2, while my XT1079 phone is obviously part of Thea series.
Discovered that through trial-and-error in several other re-installs of the original ROM, GApps, TWRP and OTAs.


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How to downgrade from Lollipop to Kitkat?
I am using Spice AndroidOne. When I purchased it, there was Kitkat in it. It automatically requested for Lollipop update which I have granted. Later it has requested for Marshmallow update. When I tried to update it, it has given an error.
Now Android OS is eating all my data (3G) in one day without my permission.
How to rectify it. And also I want to go back to Kitkat version.
Kindly help me.

Have you done any research for downgrading at all? Because the first thing that shows up at Google is this video that shows you how to do that

Your question is way too broad. Either decide to rectify data consumption issue or to downgrade to KitKat. For whichever case you choose to,  tell what have you attempted so far?  Furthermore, give us the screenshots of Settings -> Data usage -> 3G as well as Wi-Fi, only for the data consumption issue.

Unfortunately you cannot downgrade from the newest version of Android to an older version, unless you root or modify your device's permissions. Ask your carrier to see if they can flash a new ROM to your device.

What "permissions" of the device need to be modified for that? First time I hear this. Usually you just have to find a matching ROM (see Where can I find stock or custom ROMs for my Android device?) and flash that – downgrade, upgrade, or just "something different" should not matter.

this is not true at all ,this is an android device with unlocked boot-loader and have no security to avoid downgrades ,an older rom can flashed using the SP Flash tool like any other mtk device without root and without editing "permissions"


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How is an "average use" defined in terms of battery life
It is common to see better battery performance being touted as a selling point, when phones are announced and when they but the market. And the claim typically goes like "lasts xx hours on average use" or variations of "average" but conveying the same meaning. Implied, of course, is reduced frequency of battery charging and longer battery life.This is encountered in phone reviews also.
What I am trying to find out from an academic perspective:
a) Is there something defined as "average" use
b) Is there an accepted standard which profiles, say an "average or typical user" or "heavy user"
Both questions are interrelated and what perplexes me, is the freedom of misuse by companies to make claims that in no way can be verified. Logically, there should be standardized way but googling did not yield any result.
Only reference which I could find when researching screen power was Analysis of Power Consumption in a Smartphone. Section 5.4 of the paper talks of user profiles, but it seems to be hypothetical, not being backed by any reference.
"There is no profiling of usage", is also an answer if it is backed by authority or standard.
I am aware that this question may not really belong here (not sure where else to ask), but being a end user concern, trust it will be permitted and more importantly answered

I don't think there is a standard use case for any device out there. The battery life heavily depends on the mobile receiption you are getting, your display brightness and your most used applications. With those little parameters there are already lots of different battery-line graphs guaranteed. With that said, the best thing a end user can do to know the real life battery-performance is to ask actual users - so searching on XDA for the battery life threads can give you an idea how long the battery will last on different use-cases as the people often include their typical usage.

@benjaminS.Thanks.  I am well aware of what you are pointing to. My concern is around  standardization or lack of it as it appears. There is a case for defining it especially when it can be impacted by s many use variations. For example, downloading being a heavy battery consuming activity can cause significant variations in other parameters of usage. So, how much of down loading is typical....you get my drift. Trying to get an academic perspective on this. Even getting authoritative " there is no standard ",is an answer

Ok so I still got no explicit answer on this but I found some interesting information (on sony atleast). Text is too long for a single comment. When checking the product page for the M4 Aqua which is advertised with 2 days battery life they refer to some tests. Here they say that the Company named Strategy Analytics tests the devices on their battery life and back up their claims on battery life.

Further searching showed that this company has tested multiple devices - though the report is not accessible without a registration sadly. Atleast now I know that there are companies which test a lot of different smartphones on the same criteria.

@Benjamins thanks haven't gone through as I am busy  traveling. May I request you to kindly consolidate your research on the form of an answer, so that it at least  provides  a lead.  "Anand tech", also does extensive testing of mobiles and may be you can look at that also. Sorry sending this in a hurry so not linking it.. Thanks again

Findings on the battery-life claims made by manufacturers
Note that this answer can't cover every manufacturer and/or device. Information about this topic is not well documented and I had luck to find the following links and sites. If you encounter new Information then please edit this answer or leave a comment with the source of your new found information.

After searching for reasonable information it came to my mind that the new Sony M4 Aqua is advertised with 2 days of battery life.

To back up their claims they add the following lines at the end of the site:

**Battery life has been measured against Sony Mobile Communications AB’s smartphone usage profile, defined in September 2014 to represent the typical smartphone user’s active condition, including but not limited to a range of usage scenarios (calling, texting, web browsing, social networking, game playing, music listening, picture taking, picture browsing, online video watching, video recording and playback).

If you're following a few links you'll find yourself on the battery information page. At the bottom of the page you'll find exactly the statements that raised your question.

Based on multiple battery performance tests conducted between July and September 2014 in a laboratory under active use conditions reflective of the Typical Smartphone User by Sony Mobile Communications AB. Get the full story on our test results page.

So let's look at the mentioned "results page". Here we'll find some more information about the company which measures the battery-life.
Some interesting statements in my opinion are:

based on results from tests conducted by Strategy Analytics, an independent global company specialising in market analysis
verified at the time of testing
we cannot guarantee that all claims are still valid as you read this

In my opinion this sounds like "We hired a professional company to measure our devices battery-life but don't take our words as a warranty." This is speculative though. Atleast we know that Strategy Analytics is testing the battery-life for sony devices. When we head over to their website and search a little bit we can find that they do test other devices aswell.
They've also did a big technical benchmark test and a test on Smartphone Battery Performance.

where the battery performance of flagship smartphones from Apple, HTC, Huawei, LG, Google, Nokia/Microsoft, Samsung, and Sony was benchmarked, SA found that the smartphones with the largest battery capacities did not provide the longest battery life – i.e. bigger did not mean better.

Additionally we can find some testing criterias from review magazines and blogs like CNET or PCMag.
So I'm still trying to answer your question

a) Is there something defined as "average" use

Probably - but it depends and differs on who is testing the product and what criteria they are setting. I have not found a single guideline which focusses on WHICH aspects should be respected when doing a battery test.

b) Is there an accepted standard which profiles, say an "average or typical user" or "heavy user"

Generally I would say this also depends on the tester and the product they are testing. It came to my mind that different screen sizes are suitable for different usages also. On a big screen it is more enjoyable to watch a video or a movie than on a small screen - you'll probably play more demanding games on a bigger screen and so on. Take the Samsung Galaxy Beam as an example. How would you compare an average use on this device (using the beamer for 2 hours a day) to a Galaxy S6 e.g. (using the display for 2 hours a day). I think you can catch my drift. It's hard to compare because they are built for a different audience with a completly different use case. Sony e.g. says this for their devices:

Typical Smartphone User usage profile involved using the device for approximately 5 hours in a 24-hour period, for a range of typical usage scenarios (calling, texting, web, social networking, games, camera, music and video).

Please note that I'm not affiliated with the company or the websites I've linked to. I am sharing my reasearch on this field from a neutral perspective.

Thanks for initiating a good start. +1 for inviting information add ons and trust eventually our understanding grows. Please fix the shortcut for "smartphone battery performance"


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Redirect wi-fi to a proxy

i have a such following LAN: there is a PC that running proxy server on it. My Android phone is on that line. my wi-fi hotspot is on. i want to redirect my wi-fi to proxy? is it possible?
my phone is: Android 4.4 Samsung Galaxy S4 mini

Each Wi-Fi network has settings in it. There's an "Advanced settings" option there ( I can't say how exactly it's called on 4.4 as I have only 5.x devices now). In Advanced settings you can specify a proxy address for this connection. Note, that the browser settings can be different from the proxy you configure in network settings.


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Block some sources from Google Now?
I'm seeing some cards from the Daily Mail when I look at Google Now. How can I prevent Google Now surfacing cards from sources that I dislike?

Tap the menu button at the top right of the offending card, there should be an option for "Never show stories from the Daily Mail".


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Dual clock on OxygenOS lock screen
I've got the new OnePlusTwo with Android 5.1.1 and OxygenOS 2.1.2. Does anyone know how to display home and roaming clocks on lockscreen?
That was basic on Galaxy S5, but haven't found out how to do it with this one.


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A Lot of .so files (1268 files) are seen in default storage in my android phone
I have Lenovo A390, rooted and installed a custom ROM. I have been using this ROM for 4 months but recently I am seeing these lib files. Refer the sample screenshot. It keep generating after using sometime.
Default storage or junk files saved in SD card Home directory - /mnt/sdcard
Please let me know if any other info needed and tell me how to get rid of these files permanently. Also phone started responding slow and I am maintaining 50% free space in both SD card and phone storage.
Custom ROM - http://www.needrom.com/download/a390-xperia-v5-0-honami-z2/

Have you tried googling some of the file names? A quick check shows some of these related to GAPPS Google Apps Minimal Edition. Has this been recently installed?

What is "default storage"? In which path/directory do you see those files? What custom ROM have you installed? Which Android version?

.so files are native shared libraries used by some apps. If you remove them, the offended apps won't work properly. Also, they don't make your phone slow. The cause of your device slowing down is not these files.

where are those .so files located ? on sdcard ? in /data partition ? and did u use link2SD ?

@wbogacz I didn't try googling the file names and also I didn't install google related apps recently.

@AndrewT. After clearing these files, I am not seeing any change in phone behavior. Common Issue I face before/after file removal is - Slow response. Example - Dial screen takes 15 to 45 secs  to show up.

@Whereismymind That much of a lag can't be caused by .so files. They are just libraries. Still, you haven't told the exact location of those files within your phone.

@SarpSTA - I have updated in summary "Default storage or junk files saved in SD card Home directory - /mnt/sdcard "


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How to check if a device can be made root-able
There are many similar questions to what I am asking, but from my searches so far have not pointed this out:

What keywords on the device advertisement or how can I tell prior to purchasing a device, if it can allow root access to applications?

For instance, is there a brand or a model, or even OS version, that comes with an "allows Switch User" application by default?
Is there a way for me to direct possible customers to "easily" check if a device can be made rootable...
Long story:
I built a device to help users without mobility to control an Android device. The users are usually illiterate, have no Internet access and have low resources.
My application requires root access, however, my users are very uninformed about technology, and thus I need some sort of pointer or something to help them purchase Android devices (currently, they send me an e-mail that they usually can only check/reply once every 3 weeks, then I check that product, and give yes/no replies to that device.... this scenario is not working out, and giving out lists with all possible/know devices is also troublesome, since most shops will sell an Android device, but will not be able to tell the client the model.
As an example, we had the D2212 Sony E3 model working (this was my local testing device)... but clients keep on asking if the "Sony one", "the black one", "the telephony dealership one", etc.

As far as I can figure out the answer is no. I'm tagging @Izzy here to catch his eye, he'll know better.

@SarpSTA: @mentioning someone who hasn't participated in a question (by answering, commenting, or editing) won't send an alert.

@AlE. The more I know. Thanks for the heads up.

Rooting is not something endorsed by vendors (otherwise they would provide official instructions for doing this, or even ship the phones already rooted). Sony provides instructions to turn your device into a developer tool by unlocking the boot loader and changing the OS to a custom build. Motorola once offered the same. Also Nexus devices are friendly to rooting.
But in general there's no simple way to answer your question. Every user is on his own with this problem. Yes, I know this is disappointing.

Thanks for the reply, I will keep this open for a bit longer, in the hopes someone knows a trick or two how to get a hint on this.... btw, what do you mean by Motorola once offered the same, do they block the bootloader in any way? Or even prevent you from adding some sort of Super User (switch user, shell user, etc.) tool?

@Bonatti there's no trick available, and here's why: Sony Z3 can be rooted, but via the extremely painful procedure that even I, experienced software developer, didn't risk to take. Would you count it as "rootable" or not? As for Motorola, -- once they positioned themselves as "hacker-friendly" brand with easy rooting options, but I don't know the situation now.

I would count as "root-able"... I understand your pain... I am a PHP developer, fumbling about in the Android/linux ambient, trying to come up with a "backpack" device to be worn by "cerebral paulsy" patients, and then teach them, from a distance, with text only e-mails, how to root, assemble, wear and care for all those devices.... trust me, I do understand pain... still, I want to hope, even for a week, that somewhere, someone tried to make a way for an "all around insta click app", that install itself on the linux, and overrides the default ROM

@Bonatti, about that "all around insta click app" (sic), see second-to-last section of the answer for How do I root my Android device?. They are categorized under 1-click root method. Either it would be an app for Android or a software for PC, but both relies on exploiting a vulnerability to push the su binary.  They have proved useful to those devices whose bootloader cannot be unlocked or where bootloader unlocking is not supported (such as, MTK devices). Nevertheless, as said, there is no universal method applicable on every device.

How to check if a device can be made root-able[?]

If you go to a retail store and finds a device unknown to you, you, in virtually no fashion, can come to know whether the Android there can be rooted or not (exceptions reserved for 1-click root methods). The reason is simple. There are three common techniques to root a device:

unblock the bootloader, flash or boot into a compatible custom recovery and use it to place the superuser binary
exploit a vulnerability when booted into Android OS and push the superuser binary, known as 1-click root access
interface at low-level to flash a pre-rooted and device specific ROM

As you can see, the first method requires interfacing with bootloader which you can't do at retail store; the second is of course not allowed either (though you may be in luck); the third is usually not supported for all devices either and always requires a PC.
Since Android's security model is almost useless against a process running with root privileges, it explains why a device (if has to be shipped with Google Apps, it must be compatible with Android and hence, should abide by guidelines under Compatibility Definition Document) wouldn't be having a switch to change the user to superuser or give access to superuser privileges.
Is it all hopeless than?
Yes and No. The only good option I see is the Web. Use it to search about rooting your device.


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What to do when delete data option doesn't work?
I wanted to know if I can fix my Huawei tablet. It stopped suddenly and it didn't boot up normally. I forced it to boot by holding the power button and now it got stuck at Android logo. I tried wiping data but it didn't work. Any ideas?

You tagged the question with rooting yet you don't mention it in the question at all. Did you try to root the tablet and did the tablet broke down after that?

"it didn't boot up normally" -- so in what other way was it booting? Did it boot only into a screen with an  Android and exclamation mark? Consider explaining the situation from the beginning. For example, tell us what were you doing when the phone suddenly stopped? After that, if it didn't boot straight into Android OS, then what did it do after long-pressing the power button? After wiping data and after seeing the logo, how long did you wait? After a reset, It takes few minutes sometimes to have the device ready to use.


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How to block private numbers
I am getting way to many calls from marketers these days. I have listed my number on no call list and they still keep calling. Most of the time I can't be bothered to report everyone.
How to block callers from private numbers that are hiding their Id?

Per their description both Call Control - Call Blocker and  Call Blocker Gold should work.

On Android version 5.1.1 (Samsung Galaxy S6 Edge)
One way to do it is go to Phone (like you would make a call) then click on the More in top right of the screen and choose Settings then Call Settings > Call rejection > Auto reject list and select the "Unknown" option.

Hope this saves you some time.

It's probably worth [edit]ing your answer to add your device details as these options may not available on all devices (e.g. it's not available on my Nexus 6P).

@bmdixon I have added Andriod version do you think phone model is relevant too?

Yes, I've used Nexus devices for years and none of them have had this so worth adding your phone make and model. If it apples to other devices then people can comment/edit to add other info.


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Move applications to SD card in Samsung Exhibit?
I have just acquired my first Android phone -- a Samsung Galaxy Exhibit (SGH-T599N) running Android version 4.1.2 (Jelly Bean).  Because the internal storage is fairly small (only 1.34 GB) I've inserted a 16 GB SD card.  I downloaded the program AppMgr III (formerly app2sd) and attempted to move applications to the SD card; however, when I click on the "On SD Card" tab, I see the following message:

This device doesn't enable users moving apps to the SD card.  Usually, it's because of the manufacturer removes [sic] the function of moving apps to SD from Android, or a SD card is not inserted.

I see there are many similar threads for other devices, but none explicitly address the Exhibit.  Is there a way (preferably without rooting) to override the manufacturer's removal of this function?

Without rooting: No. With rooting: See our app2sd tag-wiki (and watch out for e.g. Link2SD).

It's impossible to move apps without root if this function is not supported natively. And 'overriding manufacturer's removal of this function' means you are trying to have extra access apart from native support. And that's possible only when you have root access
If you are willing to root your device, you may check this link:
http://androidforums.com/threads/root-t599-t599n-t599v.763393/


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Whatsapp encryption key location
I have an old phone (Galaxy S3 international unbrandedand) and I would like to decrypt my whatsapp backup files (crypt8, as recent as the latest backup which is always at 4 AM, I think).
I've googled many tutorials but they all seem to be outdated.
Most of them presume that the key file is located in /data/data/com.whatsapp/, however this folder does not exist on my phone.
I've also tried adb backup as root on my linux laptop (adb backup -f whatsapp.ab -noapk com.whatsapp), but when I transform this ab file into a tar and then extract its contents, it's just empty.
I've also tried to locate the com.whatsapp folder (not the user files folder with the actual *.crypt8 files, pictures, etc), but I can't find it anywhere on my phone.
Am I missing something? Are the whatsapp app files somewhere else now? Or has the location of whatsapp changed?

"adb backup as root on my linux laptop",  -- root as on Linux or on Android? If the device is rooted, then there is no need to do adb backup. Just go to the location using some root file explorer and get the file. If it is not rooted, then it doesn't matter whether you  run adb backup from Linux using root privileges or not. As for the empty backup,  WhatsApp has android:allowBackup="false" in its manifest, so ADB can't backup WhatsApp.

root on linux, I had some problems using adb without root (sorry for the ambiguity). The backup flag is bad, what options are there now? I assume there is no way to change the manifest file ...


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mount.exfat-fuse mounts drive r/o
I'm mounting an external exFat drive on a rooted Android device (Amazon Fire TV/2) using the mount.exfat-fuse program.
mount.exfat-fuse -o rw,umask=000 /dev/block/sda1 /system/test

directory permissions are 777, but permission denied for anything root tries.
Thanks for any help.

/system is read-only by default, could be related.  It's certainly not a good place to be mounting external drives.

system was mounted r/w and the location was just for easy testing of a script in xbin, but thanks for the replies.

It turned out that SELinux policy on the Amazon Fire TV/2 caused my exFat drive to be read-only when mounted, despite mounting arguments. The SELinux command setenforce can be run with an argument of 0 or 1, setting SELinux to permissive or enforced, respectively. When set to 0, the drive can be used normally.
So, I check for the presence of setenforce in my mount script and set it to 0 if found. The unmounting script does setenforce 1, putting things back as they were.

can you please post a more detailed answer ,so it can be useful as a future reference :) thanks in advance

Sure. I hope this helps someone else.