Knock off works correctly all the time but knock on works only for about half a minute or less after I turn off the screen.
Weirdest thing of all is that when the phone is charged (100% - green light , but the phone is still plugged) knock on feauture works as it should. I don't know what to think of it. It seems like a software bug but I am not sure after all.
Edit : Knock on works ok when phone is charging via pc's usb. I really don't know what to think of.