The background: I’m the developer of an app (the scrabble-playalike CrossWords) distributed via fDroid (and the Google store, of course). It was packaged by someone else, and I didn’t even know about fDroid until some users contacted me to tell me it was broken. Since then I’ve been submitting pull requests on the metadata file to keep it up-to-date.
Now Google’s banning one of the features I like best and think users will miss, play-via-SMS implemented using “data” SMS (“narrow band sockets”, for the other greybeards here. I’m making the necessary changes to remain listed on the store, but I’m NOT removing the feature from other variants, including the one for fDroid. Ideally I’d tell unhappy users of the Google Play version to switch to the fDroid version, but that’s not easy – because the two apps have the same appID, but are signed with different keys.
The Question: is there history or best-practice available for allowing an f-droid build to replace a Google build without losing persisted data (as happens if you uninstall in between.) Obviously this would require some user interaction, but I’d hope to make it really simple for them.
I’m just beginning to think about how to do this. If other app developers have been through the process before I hope to learn from them (you).