Your video uses phrases which are not standard English. The phrase 'a spaghetti' is not used. 'A plate of spaghetti' might be used in that context. Additionally the phrase "Would you please bring some water" would only be used if you have just asked "What should I bring to the game?" or something like that. In the context displayed 'ordering food' you would most likely say "Could you bring me a glass of water?" or "Could you please bring us some water?"
I fully support your effort and think this is a great tool.
I actually talked to a friend and showed him the app who was receiving speech therapy for his stammer. He told me that they are doing "similar" exercises in therapy sessions. So there may be a market, yes. I will research this subject more, thanks for the idea.
I fully support your effort and think this is a great tool.