Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Soor - Discover music a lot better on Apple Music
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
humit - A social networking app for music sharing and discovery.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home
MTME - A new way to discover music