I had my kids join Life360 to track their whereabouts, but they started tracking me, too, sending me grocery lists whenever they saw me at the store.

Life360 is a popular location-sharing app that allows family members, friends, and others to share location information with one another.

Life360 says it has figured out how to provide always-on location services without draining your smartphone’s battery. That’s a significant step forward, because most GPS services are power ...