Well, all my apps also come from the playstore;
About the iPhone version, cannot say much, and the only Android version bug I heard of is the "0 byte savegame" one, that seems to happen when the game crashes while saving. Thus, we have a "Do not turn off your computer while saving icon is displayed" issue. Problem here is that there's no save display icon, but you cannt do much here, and even without the display icon, this is of common sense
By my logic (can mostly talk about Android version): Issue is that when it needs to save, something makes it crash, and that corrupts the savefile.
- Can it be agame issue? I have three devices and haven't had that issue on them of them, but that's just me. In fact, FoS seems to load savegames to memory when the application starts, or at least it keeps a loaded vault on memory once loaded (on Android this is easy to spot since you can scum-backup and scum-restore vaults. If you scum-restore with FoS staying at the main menu, game doesn't load the file, but instead seems to load from what it had stored in memory). Probably on iOS works the same way.
- Can it be an OS issue? Android's a jungle so it's totally possible, game demands OS access in a way a custom launcher and frontend it might not like.
- Can it be a third party issues? I've had enough antivirus and firewall issues at work blocking even database backups to know it's a common problem. Maybe game saves data in a specific pattern some thir party programs do not like, like the antivirus test file 99% of the AV software is coded to recognize as dangerous. For example, when FoS tries to "dump" the save out of memory into the file, something might consider this any kind of "attack"
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And no... I haven't looked on any of the support forums... because I seem to be one of those 99+% "lucky" guys that have a perfectly working game, so I haven't had the need to complain; I just play the game.
And about those clean and dirty environments. As I said you may test your app in some "not so clean" environments (basic, commonly installed apps on most devices), but you probably won't test your app on a device you wouldn't dare to touch with a 10 foot pole. Apple's App testing is controlled by Xcode and only on registered devices, and Beth probably would not release the app on iOs (specially taking into account that it was first releaded on iOS), if all the tests weren't successful (since Apple validation comes later).