Now double tap can wake the phone. Is there a way to put the screen to sleep (lock screen) with just one single tap, instead of using the hard key?

I've been using Android-based Moto Milestone for over a year until recently switched to N9 (because it's more Linux :3), and I really missed this feature.

With a silicon case, the power key is really not that comfortable to press.

Will constantly check for replies. Thanks guys.