KitKat continues to be the most widely used version of the OS.
Google has released the Android distribution numbers for the month of December, which shows that Android 6.0 Marshmallow is now running on 0.5 percent of devices in the wild. As we have seen with all new versions of the OS, Marshmallow is moving at a snail’s pace, with a rise of just 0.2 percent from November. Nexus devices are no doubt the reason behind the measly penetration of Android 6.0, though over the next month or so we should see a sharp rise as manufacturers start bringing it to their devices.
KitKat is still leading the charts with a share of 36.6 percent, which is a slight drop from 37.8 percent last month. Lollipop (versions 5.0 and 5.1) saw a major increase of 4 percent; in an ideal world this sharp rise wouldn’t continue as OEMs would start launching devices with Marshmallow out of the box, but sadly the influx of new phones and tablets with Android 5.x is unlikely to subside in the next couple of months.
The rest of the Android market is made up of devices running Ice Cream Sandwich, Gingerbread and even the long-forgotten Froyo at 2.9, 3.4 and 0.2 percent.
Source: Android Developers