Soor - Discover music a lot better on Apple Music
ChordU - Extracts chords from any song, integrated YouTube.
humit - A social networking app for music sharing and discovery.
Guitaa.com - Turn ANY song into chords, play along with interactive chords and diagram, transpose, loop, tempo control.
MTME - A new way to discover music
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.