Yesterday I installed F-Droid, a FOSS repository for Android, onto my phone out of curiosity, and looked through the stuff its has. I came across this app just called “Worm”, where you just draw multicolored “worms” with your fingers into a black void.
It’s beautiful. One of the best mobile apps I have ever used.
I use Spotube of there (F-droid) It lets you log into Spotify so you can use your playlists and discovery stuff, but it routes the music through a different service like YouTube via new pipe. This can cause a bit of a buffer between tracks but it’s entirely ad free