You may want to check out https://synthesiagame.com/ which is a commercial product that does the same thing. You don’t have to use the guitar hero style of notes, you can turn on proper sheet music.
Synthesisa is awesome. I think it is not a direct competition to pianojacq because while similar in some ways it is different in many ways too. murbard summarized some differences in another comment better than I could. In my opinion the two apps and a piano teacher complement each other.
I find it really bad taste to promote something this way. So a developer comes here to tell his story and open his mind a little about a great tool he developed and this is the only thing you have to say?
I think you're being harsh, It was in no way a critique of PianoJacq and I personally appreciate getting an overview of what similar things are out there that I could also be interested in and how they relate
