Jan 18, 2011 10:41 GMT  ·  By

According to two prominent iOS developers, around 90% of their users are running version 4.x (or above) of Apple’s mobile operating system powering not only iPhones, but iPod touch devices and iPads as well.

ReadWriteWeb reports that the first developer, Bump, says 89.73% of its users are rocking iOS 4.x, whereas 10.25% are on iOS 3.x, and just 0.02% are running the early versions of iOS 2.x which initially added App Store support in 2008.

David Lieb, Bump CEO and co-founder, claims their user base is a very good tool to measure such statistics, as they have no less than 25 million downloads across both iOS and Android.

“With Bump, our download and usage base is so large that it should be a good statistical sample,” he writes over at quora.com.

He provides Bump’s raw data from all users between January 7 and January 10, 2011, noting that this includes all iOS devices, not just iPhones.

Binned by major rev:  4.X: 89.73 %  3.X: 10.25 %  2.X: 0.02 %

Individual minor revs:  4.2.1: 52.89 %  4.1: 27.50 %  3.1.3: 6.43 %  4.0.2: 3.36 %  4.0.1: 2.95 %  4.0: 2.94 %  3.1.2: 2.52 %  3.2.2: 0.49 %  3.0: 0.22 %  3.1: 0.21 %  3.0.1: 0.10 %  3.2: 0.10 %  3.1.1: 0.10 %  4.2: 0.09 %  3.2.1: 0.07 %  2.2.1: 0.02 %  2.2: 0.00 %

ReadWriteWeb also contacted an engineer at Loopt, a location-based social networking service, for the same purpose - see which software versions users are running the most.

Loopt says their figures are similar to Bump’s and, in fact, they reportedly have even more users on iOS 4.

According to the news source, these breakdowns go to show just how fragmented Google’s Android mobile OS really is, with only 0.4% of users running the latest release at the moment.

Admittedly, Android 2.3, also known as "Gingerbread," has just been released. Nonetheless, a similar poll conducted in December revealed that just 43.4% of users were running version 2.2 “Froyo,” the most recent version at the time.