Festify - Festify is a free Spotify-powered app that lets your guests choose which music should be played...
Openwhyd - Collect and Share the tracks you love.
Heartbeat - Listen to music with your friends together, on Spotify
Music Smasher - Find any song. Music Smasher searches Spotify, Rdio, SoundCloud, Bandcamp, and YouTube.
Join My Playlist - Listen to music live together with your friends in Spotify.
Zoff - Collaborate on a live music and video playlist with your friends.