The Solution!
"Kid, where are you?" is the new device to be sure to receive the information you need.
Even though your child often forget to tell you he's leaving school, sometimes only because he doesn't even think about it, you can receive a SMS that warn you anyway
OK, but in concrete terms ...
This application uses geolocation of your kid's phone to ensure as soon as he leaves school you receive a text message directly on your cellphone.