Mobile games usually get a bad rep as they’re usually asset flips and/or MTX-ridden and/or ad-filled, etc., and I’m sure this is actually the case for most games on the app/play store. But are there any ones that are actually good, maybe just something to pass the time with?
Hoplite
Pixel Dungeon
Tiny Folk
Unciv
Battle for Polytopia
micRogue
Doom & Dentiny
the mobile port of Chrono Trigger
and I strongly recommend the GBA and GameBoy emulators MyBoy! and MyOldboy! for playing those entire libraries on the go