According to an announcement on Twitter, HTC has begun officially rolling-out its latest OS update to its flagship device, the HTC One M8. The Android 4.4.3 KitKat update is currently only being delivered for its developer edition model; however, the update is expected to find its way to the other device versions soon. 

NDTV Gadgets also reports that the new OTA (over-the-air) update is 592.17 MB in size. Its also reported that a file of the update is currently being shared on the XDA developers forum. Previously, HTC Vice President of Management Mo Versi announced that the new update would be sent out OTA last week, and that it would include "security fixes from Android 4.4.4 KitKat in the current Android 4.4.3 KitKat update" for the M8. 

Last year's HTC One, the M7 model, also saw its developer edition updated to Android 4.4.3. HTC also provided the source code for the M7 update and the M8's update source code for Sprint's version of the smartphone. NDTV is also reporting that the other US carriers' HTC One M8 devices will also receive the OTA update "soon." 

Versi also announced that the carrier versions of the M7 will not be receiving the 4.4.3 or 4.4.4 update, as they will be updated "directly to L release for next update." "L" refers to Android L, which is the next major update to the Android OS and is expected to be launched by Google this fall, most likely on the new Nexus 6 smartphone

HTC updated the One M7 to Android 4.4 KitKat last February, and then followed it up with an update to its Sense UI (version 6) in May of this year. 

The HTC One M8 remains one of this years best phones, both in terms of critical acclaim and in sales. The device reportedly moved between 3 and 5 million units in the second quarter of this year, which is behind both the iPhone 5S and the Galaxy S5, but is still impressive nonetheless. 

Reviews have generally praised the device for it's unibody aluminum design, vivid screen and dual front-facing speakers. The device also supports expandable storage via microSD, and has a unique dual-camera system, that while not the best, is remarkable for its innovative design.