Fragmentation is a fun word to use in the mobile space. The devotees of Apple and the iPhone delight in the term because it makes Android aficionados cringe. Heck even the executives at Apple use the term at every opportunity. Some of the folks on the Android team deny it exists. However in a recently published study, most Android developers say it is a real problem. So what's the deal?
As with so many other contentious things in this world, a lot comes down to how you define something. If you write an Android application, you will have to test it on multiple devices. So I will use this as my definition of fragmentation. So obviously Android suffers from fragmentation. Here is a simple example of it:
This is a screenshot of an app running on the HTC Thunderbolt. According to some folks, it is selling quite well. What's the point of the screenshot? Well take a look at the text field right below the "Your phone number" prompt. Here is the code for it:
<EditText android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/entry_phone" android:textStyle="bold" android:inputType="phone" android:imeOptions="actionNext" />
See the problem? WTF is up with those zeros in the field? They clearly should not be there. This was the only phone I could find that produced this problem, but I will have to add code just to deal with this annoyance. This is fragmentation. Code has to be tested on many devices, and you may have to put in some device-specific things to get the app to work the same.
Now don't be fooled, fragmentation exists on all mobile platforms. Yes, even iOS. There is less of it, but it is not insignificant. Fragmentation is quite prominent on almost all application platforms. Do not get any web developer started about IE specific CSS for example.
So it is a huge problem on Android? My answer to that question is irrelevant, as the perception that it is a problem is all that does matter. I think this perception is completely reasonable. Many Android developers were programming for the iPhone in the past, and were used to testing on a single iPhone and nothing else. Thus Android seems arduous.