After purchasing iPhones, they slow after a year....after the iOS updates and especially when a new release is install. I had that experience with my iPhone4...and with my family's 5s and 6s. For me...I hate to say but I defected to a Samsung and I have had it for 2.5 years and it is just works as fine as day one. Why do iPhones slow down so severely? I really want to get back to an iPhone but that is preventing me.