One of the coolest new features on the G Pro 2 is “Knock Code,” an enhanced version of Knock On that’s found on the G2. Knock Code allows you to set up a specific “code” for tapping on your device to wake it up, which was supposedly added as a security feature.
There are a ton of different combinations of knock codes you can use to unlock the G Pro 2, and it’s shaping up to be one of the best features you’ll find on LG’s latest phablet. If you want to see the feature in action, (trust us, you do) you can check out the video below.
source: Android Central