What is the Frequent Location app? It's not really an app. Its an actually a feature of the iPhone. It would be better if it was an app. The only way to see the information is to go through a very well hidden menu. What does it do? Like the name suggest will show you a map of the exact places you have been. So basically you're being tracked. I am for one comfortable with it and if you are as well its easy enough to turn off.