Check out the Android N Developer Preview 3 Fixes, including double tap to Open Camera and all the other cool Stuff

Since its 6.0.1 iteration, Marshmallow, Android has featured this cool thing where you tap the power button twice in quick succession and the camera app will open. 
Cool eh
Unfortunately, since it came out there's been a lingering issue: if the phone or tablet is unlocked and the power button is double tapped, the device will first lock and then open the camera app, rather than just opening the camera. 
From the looks of things, in the Android N Developer Preview 3 (DP3) this is now fixed - a double tap of the power button while the device is unlocked opens the camera app without locking the device first.
Yay!
So here's how it works when you double tap to open the camera on DP3:
  • The device is unlocked: double tap opens the camera, device stays unlocked
  • Once on lockscreen with the smart lock enabled (swipe to unlock): double tap opens the camera, device unlocks
  • on lockscreen with device locked: double tap opens the camera, device stays locked
  • If the screen isn't locked, just double tap to open the camera.
Once you do that you should have no problems whatsoever, while it's not mindblowing or anything, it could be a pesky little problem and now you can use the camera without the phone locking itself and take a quick photo.
So if you're nitpicky about that sort of thing, well now you're covered.