Where in the file system are applications installed? I have installed a few Android applications both with the adb install MyApplication.apk command and via a webserver (like an alternative to Android Market).

But where in the Android file system on my phone is the MyApplication.apk file placed? Are applications installed with adb install not placed in the same directory as applications downloaded from the Market?

I found some applications on /system/app but I can't recognize them as some downloaded from Android Market or the one I have installed with adb install.

Where on the system is applications that I have installed located?

My phone is not rooted, and I am running Nexus One with Android 2.2.1.
Where an app is stored very much depends on several criteria:


System apps / pre-installed-bloatware-apps are stored in /system/app with privileged apps in /system/priv-app
(which are mounted read-only to prevent any changes). You may also find system apps in /custpack/app's subdirectories.
normal apps in internal memory go to /data/app
some apps (encrypted on internal storage?) go to /data/app-private
Apps stored on external memory go to an encrypted container in /mnt/sdcard/.android_secure. As at runtime Android needs them to be decrypted, it will decrypt them and store a decrypted copy on tmpfs (so it's gone on a reboot) in /mnt/asec
(you cannot simply look into /mnt/sdcard/.android_secure directly from the device; but if you use a card reader and attach the card to your PC, you will see the files there have the extension .asec instead of .apk -- from which you will get the connection to the name /mnt/asec).
the apps data are stored below /data/data/&lt;package_name&gt; (internal storage) or on external storage, if the developer sticks to the rules, below /mnt/sdcard/Android/data/&lt;package_name&gt;.