iOS 9 will run on any device that supports iOS 8, as far back as the iPhone 4s and iPad 2. This year’s update has few new features, instead focusing on performance, reliability, battery life, and slimming up to consume less storage. As well as more features for app developers to tap into thus creating more powerful apps. That’s not to say that there are no new features, but I’ll be covering some of these new features over my next several blog posts.
To upgrade, connect to WiFi and go to Settings > General > Software Update. If you don’t have enough storage to perform the upgrade, you still should be able to the old-fashioned way with iTunes on your Mac or PC and a USB cable.