ZenTracker lets you keep tabs on your kid's location via Google Latitude

As every parent can attest, knowing the whereabouts of your children, especially as they become more independent, can be both a source of stress and comfort. Are they where they said they’ll be and/or where they’re supposed to be?

That’s the question that ZenTracker, a location-based service built on top of Google Latitude, helps to answer. The site, a side project of 25 year old Alexis Arquilliere, offers a way for parents to track their child’s location and, more specifically, be alerted if they stray outside of a designated perimeter, such as the home or their school.

Paris-based Arquilliere, a recent student and a previous product marketing intern with Google, launched an experimental version of ZenTracker a few weeks ago, based on the limited public API of Latitude. He’s since expanded its functionality, however, following Google’s announcement at its recent I/O developer conference that Latitude would support Oauth, enabling a user’s location data to be shared securely and privately between Google’s servers and that of a third-party.

The way ZenTracker works is as follows: The child who is to be tracked runs Google Latitude in ‘background mode’ on their mobile phone (Latitude, of course, runs on multiple platforms and handsets since it’s baked in to Google Maps). Geo-location data is then regularly sent to Google’s servers and ZenTracker in turn frequently polls Google for this information, checking it against any user-defined rules. Then if the child’s location matches one of those rules, such as going too far outside the local neighborhood or not being at a specific place during an allotted window of time, the parent is alerted via email, SMS or Twitter.

Revenue-wise, while most of ZenTracker’s features are free, the actual alerts only get sent out to premium subscribers. In other words, it’s a freemium play. A subscription costs $8.95 per-month, which includes 25 SMS messages, although more can be purchased.

ZenTracker is thus far entirely bootstrapped – Arquilliere currently has a ‘day job’ – but it’s hoped that the service can get the traction needed to take it further.