If a teenager enters any known danger zones, their phone will make a sound alert and vibrate to let them know they are in an unsafe area.

BBC: Will the next Zuckerberg be female?

For those who need a literal nudge, Jawbone built in a service called "idle alert" that makes the bracelet vibrate if you sit still for more than, say, 15 minutes.

WSJ: Sit Up Straight, and Other Advice From Big Mother