Each time you press a 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
Here is a link to the Spellers Movie https://www.bitchute.com/video/W2Hd9Keyj83r/
you can watch it for free.
There is insufficient screen space to run the app on an iphone. It might load but it will not be usable.