Slackbox - Spotify playlist collaboration through Slack
PeekaBeat - Turn your selfie into Spotify playlist 🎶
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Party Blends - A way to blend your friends favourite tracks into one Spotify playlist.
PlaylistMap - Connect with Spotify playlist curators from around the world
Magic Playlist - Get the playlist of your dreams based on a song