WOW, Ive begun coming in here for useful information and gotten great feedback from most everyone. But some of the responses here blew me away. I ended up here by searching for exactly the same type of app. But the attack on the OP were way out of character from what Ive become accustomed to in this Forum. This isnt FlameWarz!
I am a Scoutmaster & have two great kids both now with Smart phones. The wife and I are most likely at the overprotective side of the parenting range.
However there have been time that one or the other has been out with someone else and either not heard their phone or in the case of school, scout, & church activities have had the ringer off.
In one particular case my 14yo son was in a carfull of other kids with a family friend and had simply forgotten to call us and tell us they were stopping over somewhere. Needless to say after about 2 hours Mom and I were getting very uptight.
So I can see a valid use for such an app. I noticed in the Android Market Life360 has an app that may well fit the bill for me. I was also concerned about the battery drainage issue as well. I plan to install it with my childrens knowledge and will report back how it works.