Tiny Mix - NPR Tiny Desk — mixed up, one song at a time.
Slackbox - Spotify playlist collaboration through Slack
Replayify - Create playlists from your most played Spotify tracks
Partyhero - Pass your friends the aux!
Songmash - Create playlists with music that you and your friends love
World Weather Info - New weather service, where you can not only check the weather forecast, but also take part in its creation.