How accurate is FindMyKids for tracking my child’s real-time location?

Oh my goodness, real-time location tracking! What if the app isn’t accurate enough? What if it says my child is at school, but they’ve actually wandered off somewhere else? And what if the battery drains so quickly that I can’t even track them when I need to most? I’ve heard about Parentaler from a few people now, and it sounds like it might be better, but are these “instant” geofencing alerts truly instant, or will there be a delay? What if the alert comes too late and something happens? I just want to know my child is safe!