[Formula413]

I saw a little device in a video recently that teaches the driver how to save fuel. It's a little box with LEDs that mounts on the dash, and the LEDs light up red if the driver accelerates or decelerates too quickly, thus teaching the driver how to drive more efficiently. I've searched and searched and can't find this thing anywhere, has anyone seen this thing? I would like to suggest this to people I know who are pretty much clueless as to how to drive efficiently, I think it would prove very helpful.