What would this kind of reader be called?

I used to have a device called a Cybiko which was basically a mix between a gameboy and a PDA. There was a program on it that was basically an e-reader, but instead of displaying lines of text it would flash each word one at a time. You could adjust the speed and it would read things like text and word documents.

Does anyone know what this type of reader is called, and do you know of any programs that would do this for the iphone? I’m not looking for the Cybiko specific one, just any that will do something similar.