@thetruthaboutvaccines I have released my free non-verbal autism app for an Ipad. https://apps.apple.com/app/id6452470821.
It is also available for windows tablets and mac tablets at https://gitlab.com/spellers/Editor/-/releases
This program was inspired by the Speller the Movie. It provides giant buttons for use by non-verbal children and adults. It allows creating, opening, saving and speaking.

Each time you press a large button the letter appears in the small edit window at the top of the screen.
When you press the speak button the line you are typing will be converted to speech and come out on the speaker of the ipad