Originally Posted by tys0n
That is because there is no support in kernel to tap while screen is off.
knockr has no problem turning on the screen. it turns off screen by making every pixel black (On AMOLED) so it can respond to double tap.
but when i double tap the screen turns on for a moment and then a blank(black) activity comes up so i have to press home button to close it.
i think that's a bug because knockr is a new beta app.
but yes i think full support like LG's need kernel support. maybe maclaw can make us a compatible kernel