I’ve been thinking about getting a GPS tracker for my daughter, but I have no idea where to start. There are so many different models out there, and each one claims to be the best. Some have real-time tracking, others have geofencing, and then there are ones with two-way calling. I don’t want to get something too complicated, but at the same time, I want to make sure it actually works when needed. Last month, a friend of mine bought one, but it kept losing signal whenever her son was indoors. That kind of defeats the purpose, right? What features should I look for to make sure I get something reliable?