Probably what the default music app should be at this point. Highly customizable and easily navigable. Its honestly a steal at $0.99 to get rid of ads.
Only changes I would make / add is an option to not blur the background and an option to hide particular buttons in the Now Playing View (Musixmatch, specifically).
Other than that, this is the perfect music app for me. Highly recommended.
David Etheridge-Bartow about Marvis Music Player