It's worth noting that (for a while), the Play Store / Play Services has offered to verify even sideloaded apps. I notice this regularly when I install a new bu

It's worth noting that (for a while), the Play Store / Play Services has offered to verify even sideloaded apps. I notice this regularly when I install a new build of Firefox Aurora. It's never rejected an update, but I believe it is looking for exactly this sort of thing. So as long as you have Google Play Services in any form, you should be covered. The more interesting question is when / how will Amazon (and other reputable app stores) deal with the issue.