Looks great technically. I am a language nerd as I have worked in multiple countries like China or Austria or the US and I am from Spain.

If you want to sell your app you will need to explain it for humans, like this guy is doing: https://www.youtube.com/watch?v=ROEJe-nBmqQ

You will need to get better at public speaking and telling stories. I recommend going to your closest Toastmasters club.