MIDI Guitar for GarageBand was just released on the Mac App Store!
MIDI Guitar for GarageBand is now available on the Mac App Store version. It is a limited version of the full MIDI Guitar product intended for GarageBand or Logic users who like to keep things simple and for those who like their software to be officially released by Apple though the Mac App Store. It’s also the lowest cost entry to the world of MIDI Guitars at a fraction of the price of a hardware setup.
More info at its product page.