Following the rollout of a firmware update to Microsoft's flagship mobile devices, Lumia 950 and 950 XL, which added double tap to wake functionality, it appears the company is now also adding the feature to its Lumia 650. On top of this, their low-end device, the Lumia 550, is also receiving a firmware update, however, the double tap to wake feature is vacant on this one.
As reported by Neowin, the double tap to wake firmware update is now rolling out over-the-air to Lumia 650 devices. Users of this device can claim the update by going to Settings > Update & security and then checking for updates. This update has also been available via the Windows Device Recovery Tool for a little while.
The Lumia 550 firmware update doesn't bring the double tap to wake feature and there's no changelog associated with it. It is likely that the update provides improvements to stability, WiFi and Bluetooth, as seen with the Lumia 950 and 950 XL devices.
This firmware comes with the version tag of 01078.00042.16352.500xx.
Let us know if you notice anything else that these firmware updates provide in the comments below!