Tabletless Graphics Tablet

I just saw this new graphics tablet except it’s not a tablet at all. It’s a little widget about size of a 9v battery and a special pen. The pen is an actual ball point pen. You take any piece of paper you want, clip the gadget at the top left corner of the paper and then draw on the paper and what you draw appears on the screen. No idea how well it works but it’s supposed to be less than $100 when they come out.