I swear, Nanny Jo would love this device (I bet there is at least one episode where she uses it...it just seems like it would suit her style)
Its called the Time out pad. It has a timer on it that goes off when time out is over. But it also has an alarm that goes off if you get off the pad...
I don't know that it would be effective for TTWD, because the timer limit is 5 minutes (I believe) but I thought it was a crazy cool discipline device.
I can't imagine if an alarm went off when I was trying to wiggle out of the corner...Of course, usually, he is watching me very carefully when I'm in the corner and I'm very limited in my movement...obviously.