I'm a speech therapist/stuttering specialist and I have to say this seems quite useful! The programmed course is simplistic, as any app-based course has to be. But I really like the library of exercises with the numbers of cues and prompts. I would definitely mention this to speech therapy clients who want an app-based tool for practice. I like that you've included voluntary stuttering and approach exercises, too. I must say that the prediction of how long it would take me to "become fluent" based on a 7-question feelings quiz made me chuckle a bit. The biggest drawback for me is the general "practice makes fluency" concept that occurs throughout the app. [Edit] Is it possible to make a free trial period? I would recommend this to people for home practice, the library of exercises especially. But they would need access to the whole library, as every person is different. Even a short trial of 7-10 days would be sufficient for a person to try all the exercises and see if it's a good long-term purchase for them.