Correct me if I'm wrong but research on traditional altered auditory feedback devices has shown that they can give significant improvement in fluency for scripted speech (reading out loud). However, spontaneous speech (phone calls, conversations, etc.) only show significant improvement to the same extent that white noise (static played into the PWS's ear) can offer. Assuming that research is correct, why should anyone pay $11.99 when there are lots of white noise apps available for free? Don't get me wrong, I'm all for bringing more of these technology-driven aids to market. Those stand alone altered auditory feedback devices cost hundreds if not thousands of dollars. $12 is a step in the right direction (ignoring the cost of the iOS device.) I plan to buy a copy and play around with it (no promo codes used).