Join My Playlist - Listen to music live together with your friends in Spotify.
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Heartbeat - Listen to music with your friends together, on Spotify
Partyhero - Pass your friends the aux!
OutLoud Social Jukebox - Control the music with your friends in real-time
TuneMeet - Chat with people who are listening to the same song