Some time ago I made this app in Thunkable, now I moved it to AppyBuilder and updated it with more options. I had to keep the Thunkable package name to be able to update it, but it was compiled with AppyBuilder.
It has been of much help to people with disabilities. It has more than 1000 downloads already. All the improvements I made are based on what they requested (more tabs for categories, edit tabs labels and colors, more preset buttons per tab, etc).
I made it when my son got his tonsils removed some time ago and he couldn’t speak for a week. He downloaded an app from the Play Store, but I noticed he was typing the same messages all the time, So I made one where he could save the most used messages, as a “quick dial pad”.
So if you know somebody that may need it, please ask them to try it and to propose new features too.