Spotify - Map shows when two people play same song at same time
keezy - A colorful soundboard. Play with music.
Playlist Machinery - Tools that help you create & organize your Spotify playlists
SoundGrail - SoundGrail Music App designed for pianists, guitarists, and DJs.
Magic Playlist - Get the playlist of your dreams based on a song
Aftertouch - Aftertouch – 3D MIDI Controller created and published by Kevin Nelson.