One of my kids is off on a two month road trip in the US in September. A few years ago, while travelling in the UK, he had a (phone) SIM which allowed us at home to watch him moving about (on a map, presumably as his phone passed towers). It was fun for everybody and he's wondering if there's anything similar available in the US. There's no requirement for journalling and he doesn't want to have to be 'checking in'; he doesn't mind opening an app, but the least intrusion on his time the better. The beauty of the UK arrangement was that it required no involvement from him other than carrying his phone.
Thanks, as always.