Spy Tec STI_GL300

This is one bad-ass tracker, built to professional (spy) standards. You do have to pay $25 a month to track the device (which makes it a bit pricey), but it's one of the most accurate GPS trackers around. It will send emails and text alerts if the child deviates from the programmed route, and it will store up to a year's worth of data in the cloud. Plus, it's got a 2-week battery life.