SmartTap is a brand new jailbreak tweak by well-known developer Elias Limneos. It allows you to use a double-tap gesture on the iPhone's screen to awaken it, and put it to sleep. You can use other gestures—like a swipe-up or a swipe-down—to unlock the device or launch applications.
The tweak is a homage to the "KnockOn" feature popularized by the LG G2 Android phone, where a double-tap on a dark screen wakes the device. SmartTap is similar, in that you can awaken your device with a "knock" gesture, but SmartTap take it a step further. Check out our video walkthrough inside after the break.