ChordU - Extracts chords from any song, integrated YouTube.
Amazing Slow Downer - !A slow down music software for Mac and Windows computers - Amazing Slow Downer
Guitaa.com - Turn ANY song into chords, play along with interactive chords and diagram, transpose, loop, tempo control.
Song Surgeon - Allows the isolation of Multiple Audio Segments Create an unlimited number of loops with a single...
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.
Riffstation - The web version is Free and you can learn how to play Chords with Youtube Songs.