• The Apple App Store is expected to grow its revenue to $30 billion by 2021.

The Apple App Store is expected to grow its revenue to $30 billion by 2021. (Photo : Reuters.)

iPhone 6S has promoted the adoption of iOS 9 to the 57 percent mark only three weeks after it was launched.

According to the latest statistics provided by Apple, iOS 9 is currently installed on 57 percent of all compatible devices that have been accessing the App store. Apple arrived at the figure by measuring its stats through iPhone users' visits to the App Store on Oct. 5.

Like Us on Facebook

The figure was presented in Apple's developer webpage showed that iOS 9 still remains high after its debut. Besides the iOS 9, the stats also showed that iOS 8 is adopted by 33 percent of devices that visit the iOS App Store while 10 percent of the users still use the iOS 7.

Apple had last on September announced iOS 9's blockbuster kick-off that broke the record initially set by iOS 8. By contrast, in 2014, it took iOS 8 close to six weeks to get past the 50 adoption percent mark, Apple Insider reported.

The main reason behind the success of iOS 9 has been said to be Apple's achievement with the IPhone 6S series.

According to Apple's statistics, iPhone 6S opening weekend saw 13 million units sold. Taking consideration of the fact that it was only available in limited markets, analysts believe that more could be expected from the device if it is available in more markets worldwide.

iOS 9 is the only update available to more devices than any other iOS in Apple's history. Previous iOS updates were larger than that of iOS 9 which came at only about 1GB. This came with a lot of data usage for users and it seemingly discouraged them from upgrading.