Double-tap To Wake Screen?

Is there any app, Xposed module, mod, etc to get the "double-tap to wake screen" feature like LG phones have?

I tried an app that woke the phone by waving in front of the proximity sensor, but that was a battery hog.

Would like to be able to wake phone without power button.

I'm running PAC ROM which does have double-tap to sleep.

Thanks for any suggestions! :)