I love the idea and have thought about doing something like this myself before, but the UI / UX does not tickle my brain enough and I can already tell I would end up ignoring this. Maybe you can think about something to make the UI more engaging or some theming options in the future? :)

I agree though. People with dyslexia might have some WILD typos, but it's not really an issue. Texting with the kind of people you mean feels like talking to a child trying to sound like an adult. Their grammar is off, they use words incorrectly, you can tell they don't understand basic concepts.