Windows Phone 8.1 Update 2 continues to be the forbidden fruit for the majority of Lumia phone owners, as this OS update is only available on new devices, but there's no doubt that all its features will be part of the upcoming Windows 10 for phones rollout.
One of the improvements that Microsoft introduced in Update 2 is a dedicated feature that allows users to lock their devices by simply tapping the navigation bar, so they don't have to press the physical lock button anymore.
A screenshot posted by WMPU shows that the PC settings screen now holds an option that allows you to “double tab on the navigation bar to turn off the screen,” so this should help you lock a Windows Phone 8.1 Update 2 device without the need for the physical button.
Needless to say, this comes in handy for a number of reasons, starting with a faulty lock button and ending with ergonomics, as it could be considered a faster way to lock your device.
This particular option also makes it possible to unlock and lock your device without the need for a physical button because settings for both actions are now available.
Waking up a Windows Phone device can be done by simply double-tapping the screen, and the very same gesture is now supported to lock the phone if you do it on the navigation bar.
Of course, only handsets running Windows Phone 8.1 Update 2 get the latter and it's really hard to speculate on when exactly the company is planning to release this pack of improvements to the other Windows Phone devices.
Microsoft has refused to provide any specifics on this until now, but expect it to ship to more devices in the coming months, just ahead of the launch of Windows 10.