FooBar2000 - https://apps.apple.com/us/app/foobar2000/id1072807669
Cloudbeats - https://apps.apple.com/us/app/cloudbeats-offline-music/id681...
Evermusic - https://apps.apple.com/us/app/evermusic-offline-music/id8853...
Albums is good for playing local files where you mainly have full albums - https://apps.apple.com/us/app/albums-album-focused-player/id...