I just heard about this app on the news.  What it does is allows kids to choose a contact in their phone list and mark them as their “companion”.  The app then uses the GPS system in the phone to allow the “companion” to see where the phone is at all times.  It will even send alerts to the “companion” if the person with the phone starts running.

With all the news about kids (especially college and high school) disappearing when walking alone, this is a great app to use to prevent that.