Pavlok

How Nagina Used Pavlok to Quit Biting Her Nails
This is just amazing, or maybe it's just really weird. Every time I've heard about using an electrical shock to influence behavior, the shock was administered by another person. Somehow it does not seem like shocking yourself would work. One, you would have to be aware of what you are doing, and many habits are unconscious, and two, I think you would develop an aversion to shocking yourself. But maybe the shock isn't that strong, so I checked:

Does the zap hurt?
The electrical stimulus is carefully designed so that it is enough to be uncomfortable, but not so strong that it hurts (and nowhere near dangerous – the Shock Clock is CE/FCC certified and 10,000 Pavlok users have proven it is safe and effective).
It's a lot like a static shock you get when you touch a doorknob after rubbing your feet on the carpet.
You can also use vibrate and beep if zap isn't for you!

I haven't gotten a static shock in a long time, but the one I remember was likely the King Kong of static zaps. I've had plenty of others that weren't worth mentioning.

You can get a Pavlok from Amazon. Via Medium.