My limited experience with Released versions is that I get an error that reads something like "Sorry the app has ended" which you can only ask where the user was at in the app. I would assume a crash report is produced that explains the error. I know I probably need to read more on the net that would probably explain all of this to me but since we have experienced developers, as you sound like you are, on this forum I thought I would pose the question here. The crash report if one is produced I think would be more geared to a Java programmer and not B4A. Any information would be greatly appreciated.
As a side note what scares me is the number and releases of Android devices that one needs to deal with. In my old world it was in a closed environment. I know that the Emulator in the Designer would be of some help with this and also a lot of QA is needed.