Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Fit Meet - Find patterns for any sports or activity.
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
Rovo - Rovo – Find Sports Buddies is a simple and easy-to-use social app that is designed to meet new strangers for sports.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home
FitMatch - FitMatch – Find Workout Buddies and Fitness Friends is a complete social communication app that connects you with people who share their fitness stuff.