Alot of my apps don't go to Google Play, I email them or install them myself. Lets say I re-purpose an app, change the name, icon etc. The user would be prompted to update and would get the different app. Now if they deleted it and reinstalled the original apk, do they get the original app? Then they would just not update. Since I use mostly server, if I delete the app from control panel, it could stay on a phone forever? Or they could re-install it from an email at a much later time? An example would be if a company was paying for an app and you had a collaboration going where they had the app on their phone as you were building it, then they decide not to pay, is there a way to wreck the copy on their phone?

Well, because the app would pull data from your BT server install, deleting it should in theory blow up the app. So, here's what I would do: Delete the app from your control panel. Email the rogue company and as ask them to hit the refresh button, because you've decided to let them keep the app if they let you have your logo on the front for your portfolio. After they hit Refresh, boom, there goes the app. They'll get an error saying 'Invalid Config Data' or the like. Not exactly ethical, but neither is refusing to pay :) // J