Most of people nowadays carry smartphones around with them wherever they go, and while this is useful for a multitude of reasons, it means if that so-called Kodak moment arises, it will not be missed. As time goes on, smartphone cameras have gotten much better, and through the last couple of revisions of iOS, Apple has experimented with ways to make it easier for iPhone, iPad and iPod touch users to quickly take a shot with minimal fuss. iOS brought he camera button to the lock screen, which has since evolved into an icon/slider, but if that still isn't quick enough for you, jailbreak developer flux has come through with a nifty tweak called QuickShoot which allows you to take a shot almost instantaneously by tapping that Camera app icon.
