Could somebody suggest a good data monitoring app? I have a friend that has been going way over on his data plan for the last couple months and can't quite figure out why. He isn't a "power user" by any means, doesn't stream music, hasn't used Facebook in a month. He pretty much just uses SnapChat, fantasy football apps, and some light web browsing. I don't have access to his phone so I can't mess with it and figure it out myself. Thanks!