As platforms such as firmware and OSes update users are urged to download the new versions and patches, but as time goes on the number of adopters of various patches and updates begins to diverge. In industry parlance, this is known as platform fragmentation and Google Android appears to be fairly much steeped in it. According to an informal survey, outlined by a PCWorld article on the subject, less than 0.4 percent of Android devices run 2.3 (Gingerbread).

Unlike Google, Apple does not release exact figures of how many people run the various versions of its mobile OS. But David Lieb, chief executive of Bump, the app that allows you to swap data with other users by bumping two devices together, says that its download and usage base (estimated at around 15 million downloads) makes it for a representative sample of iOS users.

According to the figures from Bump, 89.73 percent of the app’s iOS users are running iOS 4.X, with just 10.25 percent stuck with the older iOS 3.X (pre-multitasking). Breaking down the 4.X segment, the figures show that a majority of users (52.89 percent) run iOS 4.2.1 and more than a quarter (27.5 percent) run iOS 4.1. iOS 4.2.1 was publicly introduced in November 2010, meaning that a significant number of iOS users are already running the latest version of the OS available.

That Android platforms would become fragmented isn’t entirely unexpected and has been a long standing point of contention between Apple’s iOS and Google Android on the open market. Android happens to rest on a shotgun scattershot effect where it licenses hardware across a giant ecology of devices, whereas iOS only works within a carefully cultivated garden of Apple devices.

What does this mean for Android developers?

It means that developers cannot assure themselves that a large enough amount of the Android using population have adopted the newest features and that if they produce software for them they won’t see much in the way of returns on their work. At least, that’s the fear that I would have as a developer.

We’ve seen this issue come up before when CEO of Apple Steve Jobs went on a rant about open vs. proprietary platforms (mentioning Android’s fragmentation) and Andy Rubin, Google’s Chief of Android, jabbed back on his Twitter account and even TweetDeck weighed in back in October.

Some devices, such as the Nexus One and Nexus S receive updates within days of their release, while others suffer under the timetable of their carriers. Android 2.3 released in December but we’re only seeing an adoption rate of 2.3%. I don’t think a comparison based on such thin details is that fair, especially noting it’s only been a month and few devices shipped with and fully support the new Android—while iOS 4.2.1 had a month head start.

Give it another few months and the adoption rates will probably shallow out; although, it’s hard to say exactly how much with the scant details and data available on Apple adoption.