My 6s running 9.2.1 has this really weird issue where every once in a while, the screen freezes. I can't do anything - pulling down the Notification Center or swiping up the Control Center does nothing (does not work), and moving things around the home screen does not work as well. I can only wait until it "unfreezes", which is usually about a second or two, or turn the iPhone off and on. It's driving me crazy! There are also (less often) times when the NC and CC stops working altogether, and the only way to get it back is doing a full restart. I can't figure out if this is software-related or something wonky with my iPhone. Does anyone else experience this same issue? It happens about one or two times a day and is random, seemingly, but most of the time, it seems to happen when I exit an app. Thanks!