how to capture any .apk download We are seeking a reliable method to get the .apk file for any arbitrary application that may currently exist on Google Play store. ("legit" reasons may be e.g. to later restore to application v8 even if only application v11 is available to public).

I am not aware of any utility that can do this, so one approach might be to capture all packets which cross your wireless network to your Android device, like when the user installs an app from Play store. So we want to see if it's possible to capture all .apk files downloaded to the Android device upon user install from Play.


which wireless capture utility should you use (e.g. pcap?), and should it be run from your Android or some other machine?
how do you reassemble a .apk file from a sequence of frames?
Is there any encryption of data that would prevent the capture of the .apk file?
Is there an easier way to get an .apk? Tried the emulator but it doesn't work for all apps. adb backup gives a compressed .ab file, but we want the .apk itself in extracted form, and not buried in some .ab compressed file.
Why so difficult? Simply install AppMonster Pro Backup Restore (yes, the Pro version -- the free doesn't do this automatically), and on each install/update the corresponding .apk file is automatically backed up to your SDCard. You can configure the app to keep all .apk files, or only the latest N (number freely configurable), even pinning of a "stable version" to always keep is possible.

 

AppMonster only takes care for the .apk files (not for app data). As a side effect, it even shows you if an app contains an ad module, and you can have it notify you if an just installed app can be moved to SDCard via App2SD.