Chumpy, my PALS (BTW PALS is singular - person with ALS), had an iPad and Predictable.
The reason we chose predictable was that at the time it was the only text to speech for iPad that would support a switch.
Funnily enough, by the time Chris's hands were gone and we needed a switch the new IOS that had come out fully supported switches, so we could have used any other cheaper app. Still I like predictable for lots of it's functionality so that was fine.
With a switch (and tablets will work with them too) as long as you have a muscle you can move, you can operate the device. It works similar to eye gaze systems, except you touch the switch instead of blinking. So it could be a finger, hand, elbow, toe, knee, shoulder or head movement. They are very sensitive and need very little pressure.
So I would look at what kind of interface your PALS prefers to choose the actual tablet device, then try some of the apps for the one you prefer, and then add a switch when it is needed. Or start with a switch and get used to the way of navigating as it does take a lot of practice and patience, and getting the settings in a way that suits you.
