Unfortunately, the state of Android music players is not great. Currently I have two FOSS music players installed: Metro Music Player (the F-Droid version of Retro Music Player) and mucke. mucke has a ton of really cool features that improve the shuffle experience but it's actually worse than most apps at pulling album art. Retro/Metro has beautiful UI, and has pretty good features for customization, but lacks the cool features mucke has and is less stable. Both have more than one annoying bug, but it took me a while to find music players that had this few dealbreakers.