Since simple mobile tools will soon become a spyware and I use 3 of their apps regularly, yesterday I installed F-Droid after reading many Lemmy recommendations.
Wow, I'm pleasantly surprised.
A new app I've tested is Spotube (Spotify open source alternative; edit: apparently it uses Spotify metadata but it streams from YouTube. My bad.).
The dev said a couple of weeks ago that they're planning on closing their Google Play Developer account, so using the fork means you'll be able to keep up with new releases from that point.