I need some help with the apk

hi, i’m new in this forum, and if anyone, or someone could help me, i’d really appreciate it. First things first, we, my groupmates are having a lot of trouble with the apk program and we’re wondering if we can modify the apk in the way we want how the program works, like the user interface the amount of liquid that will be poured, etc. We really are asking of your help if this we want would be possible. thank you for your great help!

I’m sure you can modify the apk all you want as long as you don’t distribute the modified version and claim it as your own. However, you’ll need to re-sign it before installing it again, but I’m assuming if you want to rewrite some code, that you’re familiar with that process.

http://developer.android.com/tools/publishing/app-signing.html