Prodigal Music Player app for iPhone and iPad
Prodigal is a free (as free software, not free beer) and open source music player.
Bring a classic way to view your music library.
Support upload music file via iTunes
Customizable themes which allow you change APPs appearance on your own.
Get source code at - https://github.com/SpongeBobSun/Prodigal-iOS
Note - this app does not allow you to download music.