iPhone users - for good and for bad, the iPhone is much more tightly controlled.
I currently think it will NOT RUN on an iPhone. This app uses several "extensions" which apparently do not function in the iOS app. I will try to test it soon.
If you want to try to test it --
For iOS/iPhone, you have to make a bit of an effort to load it. Also it will not be a permanent app, but only run within the MIT Ai2 App on your phone. Some day this might change.
Create an account with MIT App Inventor 2 on a computer.
Download the .aia file from this website to your computer -
https://drive.google.com/file/d/1ceLXvHEBaKJy8UA_jpnd945X9WvT2Jd2/view?usp=sharing
Download the MIT App Inventor Companion app to your phone.
In MIT App Inventor on your computer, open the FonBot .aia file. *
Load it to your phone with the Companion app (use - Connect, AI companion)
*NOTE - this will take you to a page with three folders - just click Download and it will download the intact .aia file.