on android mobile there is a text to speech app (the opposite) named '@voiceapp'
I don't know any free engine for speech to text. There are apps on windows (onenote), Chrome is able to manage that too but I never tried.
I've just found list of speech to text recognition software on wikipedia.

I know it's a hard topic as I tried something with that too.
That should be the opposite for helping dys people ...
It's not easy but in case someone knows :slight_smile: