nexusIf you ask me, the double tap to wake feature is something that I miss most on my Xiaomi Mi 4. I've been an ardent advocate of the feature ever since I first used it on the OPPO Find 5 (which, mind you, remains to be my favourite phone), but for some reason, Xiaomi hasn't yet implemented it on their smartphones, including their flagships. Which is a bit of shame, because even the ultra-cheap devices with no real aftermarket support are offering the feature. Anyway, lets get to the meat of the matter, i.e., the Google Nexus 6.
Traditionally, a rooted phone was required if you wanted to add functionality like double tap to wake, swipe to wake, etc for obvious reasons. However, thanks to XDA Forums user qwerp_, users of the Nexus 6 can now wake their devices with a double tap on the screen. And guess what, you don't need to have a rooted device! There's one catch though, you'll have to have an unlocked bootloader on your Nexus 6, and have popular custom recovery -- TWRP -- installed. Now, there are chances that if have the Nexus 6, and even know what a custom recovery is, your phone is rooted. However, that's not a requirement; so, greater number of users can access the feature.
In the dev's words, here's what you have to do to get double tap to wake working on your phone:
backup a copy of
then copy the attached power.shamu.so to /system/lib/hw/
change the permission of power.shamu.so to 0644
In other words, you first take a backup of the original power.shamu.so file located in /system/lib/hw/, and then replace it with the modified power.shamu.so. Please note that the .zip file (while writing the article) is NOT a flashable zip; don't expect your phone to magically start waking to your taps unless the file is manually replaced. There are two ways of going about it: (i) TWRP's file manager, which means you do not require root and (ii) any root file manager on Android, which means you will require root. Also, regardless of what method you go for, do not forget to change the permissions of power.shamu.so to 0644, else you will not have the feature running.