Spotify - Map shows when two people play same song at same time
Muzzy - it’s a tiny and gorgeous iTunes companion that lives on your menu bar. For Mac OSX, its free!
Noon Pacific - The week’s best music handpicked & delivered to your devices
Skip Tunes - Control iTunes, Spotify, or Rdio from your Mac's menubar
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Plaaying - Share, control, and keep on Plaaying music on your Mac.