Three feature suggestions:
1. Some sort of fullscreen mode (option to have player always on top perhaps)
2. Play queue, like Spotify, for example if I'd like to play a couple of tracks but not change the order of the playlist
3. Some kind of search/filter in the playlist, so that if I add my whole library but I just want to listen to a specific Dylan track I could just temporarily filter out everything not containing 'Dylan'. There is something like it right now, but more of a navigational feature.
It's a brilliant player. Simple, easy, it's nigh on perfect. A bit more playlist search;)
