iOS 6, the latest version of Apple's mobile platform, was released on Wednesday, and the operating system is already on 15 percent of Apple devices. The news contrasts Google's Android Jelly Bean and Ice Cream Sandwich, which do not have widespread adoption on Android devices despite the former having been released during this past summer.

Ad network and data analytics firm Chitika published a reported revealing the 15 percent share across iPhones, iPods, and iPads. It took 24 hours for iOS 6 to reach a 15 percent install base; in contrast, iOS 5 took five days to take 20 percent of iOS' market share. The figure will probably climb throughout the week and into next as iPhone 5s sell from today.

iOS 6 is available over-the-air, no doubt expediting the rate of adoption. It may be a little surprising that Apple is making a major version of iOS available over the cloud, though users can plug iOS devices into iTunes too. 

On Android, Chitika also noted that Android 4.1 Jelly Bean sits at 1.5 percent market share. The software was released in June; getting it and another recent version of Android, like 2011's Ice Cream Sandwich, on devices has been a consistent problem for Google. Part of that problem may be due to the number of different Android devices available from several OEMs. Apple offers only three smartphones, four iPods, and three iPads.

The news reflects the demand for iPhone 5: the device sold out on Apple's website in an hour. Comparatively, Apple's iPhone 4S and iPhone 4 took 20 and 22 hours, respectively, so the new two-tone design and Apple's own mapping service seemed to have generated demand. iOS 6 is available to download now via iTunes or over-the-air directly on devices for free. iPhone 5 goes on sale today, Sept. 21.