The iPhone 5s is not a radical departure in design for Apple, save for one very important feature. No, we don't mean the new Space Gray and Gold colors. We have in mind the home button that has been on iPhones from day one, is now turned into a fingerprint scanner dubbed Touch ID. It lets you unlock the phone and authorize purchases, safely storing your fingerprints in the A7 processor itself, out of the reach for anyone but a few default iOS 7 apps.This A7 processor debuts on the iPhone 5s as the first 64-bit mobile chipset in use on a commercial device, utilized by the latest flat and minimalistic iOS 7 that has been rewritten to take advantage of the 64-bit system. It sports a dedicated M7 co-processor for always-on motion sensing, too.The iSight camera stayed 8 MP, but is much improved, with larger pixels, wider aperture, and the ability to shoot slow motion videos, not to mention the dual two-tone LED flash on the back that strives for natural skin color representation.