I am making a system in which the users can create Android applications. I want them to give an option to download a debug apk so that they can try it out first. After that, they have to pay for it to get the apk in release mode, so that it can be distributed in the Google Play Store.
I of course don't want them to be able to reverse-engineer the debug apk so that they can extract the needed files from it and then sign it themselves. Hence my question:
Is it possible to reverse engineer a debug apk to extract the classes and everything needed to build it in release mode?
If so, would there be any way to secure the debug versions so that it isn't possible anymore?