Good on android are also unciv, feudal tactics, beat feat and flowit!
Not Foss, but free without ads or trackers FOSS and my all-time favorite is “Simon Tatham’s Puzzles”. This is so addicting I go through a cycle of playing it obsessively until I have to delete it and wait a few months until installing it again xD
ETA: thanks for providing the sources. Couldn’t find it on fdroid because of the different name :)