This device is a gimmicked pad. It's simple in it's workings, but since it's conception 2 years ago, I've used it everywhere, from nightclubs to stages with great success.
There are no complex mechanisms to go wrong, no technology to fail, this is a pure, invisible gimmick which allows you to achieve a multitude of impossible effects with ease.
You could set the pad up to satisfy a full act with a variety of routines. A real mind-reader would appear to require no props to read minds. All a real mind reader would need is a pen and paper.
All you need is a pen and this pad of paper to make that a reality.