Magic Playlist - Get the playlist of your dreams based on a song
MusicButler - Get notified when your favourite artists release new music
Spotalike - Spotify playlist with similar songs, according to Last.fm
Tracknack - Tracknack uses album credits to find new music you care about and updates a Spotify playlist for you automatically.
Spotify - Map shows when two people play same song at same time
Album Tracker - Album Tracker automatically scans the song that is playing on your computer then shows you the...