Google has started rolling out Android 4.4.4 KitKat (KTU84P) update for the Nexus devices and also released factory images for these devices including Nexus 5, Nexus 4, Nexus 7 and Nexus 10. It released Android 4.4.3 (KTU84M) update for the Nexus devices earlier this month. The new updated is for security fix, so there are you won’t see any changes in the UI.
According to FunkyAndroid (Via), this update fixes recently discovered vulnerability in OpenSSL and fixes some unrelated bugs in logging and security. Google released the Android 4.4.3 update for the Google Play Edition devices soon after the update rolled out for Nexus devices, so the new KitKat update is expected to roll out for GPe devices soon. It is not clear if Motorola that started rolling out the Android 4.4.3 update earlier this month would skip this update to push out the 4.4.4 update.
The Android 4.4.4 update for the Nexus 5 is now rolling out, and other Nexus devices should get the over-the-air (OTA) update soon. You can download the factory images for these devices from the Google Developers website here. This will wipe your device clean, so remember to backup your device before flashing.