The Android 4.4 Kit Kat update has begun rolling out to Google Nexus 4 handsets, including Nexus 7 and 10 tablets.

The latest mobile operating system that came pre-installed with the Nexus 5 has now rolled out to all Google Nexus devices. Google also pushed out a further bug fix update for those who already have Android 4.4 KitKat build KRT16S installed.

The upgrade is available now via over-the-air (OTA) update. Nexus 4 owners can access the update via the handset's settings.

Moto X owners on Verizon have also begun to receive the Android 4.4 KitKat update yesterday.

Meanwhile Samsung Galaxy handsets owners are only just receiving the Android 4.3 Jelly Bean update.

There has been no official word from Samsung or Google on when the updates for the Galaxy S4, S3, Note 3, or Note 2 devices will be available.

This means that the update will not be arriving any time this year and that it is most likely to arrive in 2014.

Samsung is already rumored to launch the next-generation Galaxy S5 device in early 2014. That device may come pre-installed with the Android 4.4 KitKat.

Meanwhile, HTC has already announced plans to roll out Android 4.4 KitKat to its flagship devices. The company said HTC One owners will start to receive the update by the end of January 2014.

Sony also updates its customers on the progress of the roll-out, stating that the Xperia Z1 and other devices will indeed be receiving an upgrade.

Google has launched the Android Quick Start Guide for Android 4.4 KitKat on its Google Play store.

The 53-page guide details information on the new features of Android 4.4 such as Google Now and Tap & Pay features.

The new Android 4.4 KitKat features are as follows:

• Refreshed interface with translucent status and navigation bars on home screen and white status bar icons/text, ability for apps to trigger the translucent appearance.
• Optimizations for performance on devices with lower specifications, Low RAM device API
• Printing framework
• NFC Host Card Emulation for emulating smart cards
• WebViews based off Chromium (feature parity with Chrome 30)
• Expanded functionality for Notification listener services
• Public API for developing and managing text messaging clients, ability to specify a default SMS app.
• New framework for UI transitions
• Storage access framework for retrieving content and documents from other sources
• Sensor batching, Step Detector and Counter APIs
• "Immersive" full screen mode, software buttons and status bar accessed with an edge swipe gesture
• Audio tunneling, audio monitoring, loudness enhancer
• Built-in screen recording
• Native infrared blaster API
• Expanded accessibility APIs, system-level closed captioning settings
• New experimental runtime virtual machine, ART