Did you know you can lowjack your kids? Bosieboo's Out of Distance Monitor sounds an alarm if your child goes out of a preset distance, from 3 to 50 meters (roughly 10 - 165 feet).
Lowjacking them may seem like a strange way to let your kids have a little independence, but we can see the use for this in very large parks, or at festivals or county fairs, when you want the kids to poke around a bit, but also want to make sure they aren't too far away.
We know the larger of the two units is for the parents, and the smaller one is put with the child - no word on how, exactly. Glued on, maybe? Certainly if it is just a wrist strap it would be easy for them to slide off and drop (if you are raising escape artists), although maybe it is small enough to be clipped into a pocket.
Boiseboo's Out of Distance Moniter is £34.99.