Regarding the Adafruit Bluetooth module: I would have loved to integrate a 'bare' bluetooth module and avoided using a breakout board for both cost saving and cosmetic reasons, however I didn't want to get into flashing the bluetooth firmware. If I release another revision I will try to integrate a discrete bluetooth module. For a proof of concept I think I made the right decision as the breakout board was really easy to use.
The Posture Pack also badly needs some haptic feedback. Although I spend the majority of my time next to a computer I'm curious how effective this would be walking outside. It would be easier to use as you wouldn't need to change bluetooth from laptop-phone etc.