Earlier this month, Google affiliated Nexus devices received the KitKat update. Now the OEM (Original Equipment Manufacturers) partners HTC and LG have begun releasing the new chocolate-wafer flavoured OS to their flagship models in select regions.

After rolling out KitKat Update, HTC One Google Edition, US arm of the company announced the arrival of new OS update to original model (with Sense UI) and developer versions of HTC One smartphones.

"HTC One Unlocked and Developer Edition owners - your Kit Kat roll out starts today! Let us know your favorite new additions", HTC USA tweeted.

The update is available via OTA (Over-The-Air) and is said to come with HTC Sense v5.5 UI. New features include smart caller id, new Hangout message app (now all text, image and video based messages are all grouped together in a single hub), enhanced memory and power management, improved voice search, wireless printing ability and many more.

Apart from US, the company has confirmed to release the new software to the flagship model in the EMEA (Europe, Middle East and Africa) regions by the end of January 2014.

LG G2:

One of the Google's close OEM associate, LG has also reportedly began rolling out new KitKat update to the company's 2013 flagship model G2 in South Korea.

The software is currently available for download via PC suite LG Update Tool, instead of Over-The-Air (OTA) service, reported technology blog, GSMArena.

The new OS update for G2 is currently limited to the South Korean market; other global regions are expected to receive the same firmware around March 2014.

LG representative Court Elliot has said that KitKat software would be released to G2 (both unlocked and carrier variants) in Canada in late Q1, 2014, reported Mobile Syrup.

In related news, Samsung is rumoured to release the KitKat update to its flagship models early next year. Galaxy S4 and Note 3 are slated to receive the new OS update by January end, whereas Galaxy S3 and Note 2 by April end.

Japanese smartphone maker, Sony has also stated to roll out new Android KitKat update to its flagship models Xperia Z1, Z Ultra, Z, Xperia Tablet Z and ZL, ZR and SP, but refrained from revealing the time frame.

Brief description of key features of Android v4.4 KitKat OS:

Improved Caller-ID: If a caller receives a call from unknown number, the phone will look for matches on the net with local listings via Google Maps.

Priority Contacts: The new OS empowers the phone to automatically prioritise contact list for easy access, based on the frequency of the peoples' contacts to which users talk.

Immersive display: To enhance entertainment factor, the new  OS comes with immersive mode, where the status bar and navigation buttons disappear in to the back ground while you play music, games and read e-books. Users can just swipe the edge of the screen to bring back the utility buttons.

Enhanced Message grouping: Like Apple's iMessage feature, Google has brought in some improvements to the new Hangouts app; now, users can find all their text SMSs and MMSs, audio and video call details all at one place. They can also share location and send animated GIFs.

Emoji Characters:  Initially users had to install third party app to use colorful characters in their SMS. Now, with KitKat, the keypad comes with native Japanese Emoji emotion icons.

NFC and Wireless Printing: Google's new OS comes with improved Quickoffice app where-in people can create and store word documents online as well as print files wirelessly on NFC-enabled HP printers.

Bluetooth MAP (Message Access Profile):  This feature enables android devices in cars with Bluetooth support to exchange messages.

Multi-tasking:  With efficient memory management, users can multi-task by opening multiple applications; Listen to music while you can browse through the net.  

Performance: With low system requirements the new KitKat OS is expected to bring performance enhancements and also increase battery life.