Fragmentation has been Android's issue for a long time now. There are so many Android devices in different form factors with different versions of the Android operating systems. Google has been taking all the right moves recently in order to prevent this issue from spreading even further and possibly make it less of a problem in the future. This problem has been seriously affecting developers for years now. Google offering their applications on the Google Play Store definitely helped, along with the Android 4.4 KitKat's release which offered support for lower-end smartphones.
OpenSignal gave us some insight on Android fragmentation in their latest report. For those of you who don't know, OpenSignal is a company standing behind behind an application which creates maps of mobile phone network coverage, it has been available for Android for quite some time now and it is even available on iOS since last year. They don't gather data from the network but from the users themselves and then opens it up for anyone to see. The data provided by OpenSignal is kind of staggering, there are 18,796 "distinct Android devices" this year while there were 11,868 last year. Open source surveyed the last 682,000 devices which installed the application in order to gather this data.
According to OpenSignal's data, Samsung is far ahead with 43% and is followed by Sony with 4%. As far as operating system versions go, 20.9% of Android users have Android 4.4 KitKat installed, majority is still on 4.0 Ice Cream Sandwich and 14% is still below that version of Android. Compared to iOS this looks bad of course, but keep in mind that only Apple's own products carry iOS, so these numbers aren't exactly surprising considering that fact. iOS7 is installed on 91% of iOS devices, followed by iOS6 which can be found on 6% of them with the remaining 1% of devices is below that version.
Keep in mind that this data has been pulled from the devices which have installed OpenSignal's app. That's a lot of data, but it is still not exactly representative as it's supposed to be considering the amount of people who have installed the application of course.