Playlist Machinery - Tools that help you create & organize your Spotify playlists
Spotify - Map shows when two people play same song at same time
Poolside FM for Mac - An infinity pool of summer sounds in your Mac menu bar
DiscVibe - Create personalized and contextualized Spotify playlists
Listen for Mac - Add songs to Spotify playlists using keyboard shortcuts
Ranked Records - Create Spotify playlists with all an artist's songs