Spotify - Map shows when two people play same song at same time
ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
SOUNDS - Discover music with friends
Hyperlax - Sit back. Relax. Explore faraway places. Enjoy the music.
Songlink - Share music with anyone.
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.