last-slack - Display your scrobbled tracks from last.fm in Slack
Bowtie - Bowtie is a desktop accessory that allows you to see and control your music (iTunes, Spotify...
Owlead - Grow your Twitter with valuable followers, effortless
Muzzy - it’s a tiny and gorgeous iTunes companion that lives on your menu bar. For Mac OSX, its free!
Sound Control - App-specific volume control
Magic Playlist - Get the playlist of your dreams based on a song