In all of the posts I've seen here on Lemmy, it seems like Fairphones are the most frequently recommended phones; however, whenever people are asking for OS recommendations, GrapheneOS always seems to get the loudest endorsement. Since GrapheneOS doesn't run on Fairphones, I wanted to see what OS's people are actually running on their Fairphones. Is there a clear "best choice" here?

I recently made an iOS app that I’d like to distribute the source code for. I was initially going to license it with the GPL, but I read that apparently Apple’s App Store isn’t compatible with the terms of the GPL. Is there something that’s typically recommended by the FOSS community for this situation (other than just not distributing an iOS app)?