AudioRetoucher - AudioRetoucher is a tool for analyzing music, changing tempo and pitch in real time
ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.
ChordU - Extracts chords from any song, integrated YouTube.
Guitaa.com - Turn ANY song into chords, play along with interactive chords and diagram, transpose, loop, tempo control.
Amazing Slow Downer - !A slow down music software for Mac and Windows computers - Amazing Slow Downer