Noiseblend - One-tap music for every occasion, with Spotify Premium
Until AM - DJ in your browser with this SoundCloud music mixer
22tracks - DJ curated Spotify playlists on iOS
Fretello Stage - Jam, record and share your music in the blink of an eye
Spotify - Map shows when two people play same song at same time
Songlio - Free musical guessing game: race friends to name that tune