the iPhone 5S is an iterative improvement over the iPhone 5. With constant calls for it to innovate more, there is a danger Apple is falling behind the smartphone competition, particularly with the Android tsunami threatening to drown it.The iPhone 5S will be available to order on 20th September 2013 from £549.In the hand the iPhone 5s feels much like the iPhone 5, with the 7.6mm depth and 112g weight giving a lightweight yet premium experience.In classic Apple style, Touch ID is easy to set up as you tap and circle your finger to capture multiple fingerprint angles. In fact, setup is a bit like a video game that collects more prints the more you tap. After that, you scan your fingerprint and voila, you’re in. The entire setup process takes a minute or less. Log-in is as quick as clicking.The power button is still at the top, next to a 3.5mm audio jack. The volume buttons and mute switch are still on the side and the Lightning connector is still found at the bottom – all in all a very similar looking handset to the iPhone 5.The rear camera sensor is around 15% larger than the outgoing model, and uses 1.5 micron pixels for improved low-light shooting. The f/2.2 aperture is larger too, and is paired with a twin-LED flash for even more light when shooting in dark conditions. Apple calls it “True Tone”, with one cool white flash and a second warmer amber LED that automatically adjusts depending on lighting conditions for the best picture.The iPhone 5S will launch with iOS 7, the latest version of Apple’s mobile operating system. It’s a major visual departure for the software, with a pastel colour scheme, flattened icons and no more skeuomorphic elements.