Apple on Monday started rolling out the latest iOS 8.1.1 software update for the iPhone, iPad and iPod touch devices. If you're jailbroken, stay away from this update as it plugs the Pangu8 jailbreak.
iOS 8.1.1 build 12B435 contains a whole bunch of bug fixes and general performance enhancements aimed at improving the mobile operating system's stability. You can apply the update over the air by going to Settings > General > Software Update.