Rapid adoption is the name of the game with iOS 9 as two out of three compatible devices are now running the latest version. iPhone and iPad owners had been somewhat reluctant to upgrade when iOS 9 first rolled out, but the latest update changed that.
The iOS 9.0.2 update fixed a lot of bugs and adoption shot up once it was released.
Android has many more devices deployed than iOS but the latter generated more revenue in the latest quarter. According to Opera Mediaworks. Apple accounted for 52.1 percent of ad revenue generation in the third quarter.