Digital Brain Instruments "Plug-In Channel Strip" for Mac OS X Now Free (Until 2015; then discontinued)
Digital Brain Instruments is offering one of their first audio tools, Plug-In Channel Strip, for free until 31st December, 2014. After this date PCS will be discontinued. It did cost $10.
Plug-In Channel Strip is a standalone software application conceived for music production, live sets and rehearsals. It makes it easy to set up a plug-in channel strip preset ready for the game.
It allows real-time processing your microphone, instrument or virtual instrument through 8 VST plug-in modules.
Price: Free. It's available for Mac OS X 10.6-10.9.