Positive Grid, maker of the leading mobile guitar apps BIAS and JamUp, proudly announce the release of two amazingly robust, fully-programmable Bluetooth MIDI foot controllers with I/O features for iPhone, iPad and Mac: the BT-2 and BT-4 foot controllers. Guitarists, bassists, pianists, vocalists and music producers will now have hands-free control over their iOS and Mac apps using either a two- or four-button wireless foot controller designed to provide total freedom and reliable operation in any live performance, studio recording or rehearsal situation.