In an update to its developer webpage, Apple revealed 90 percent of devices visiting the iOS App Store over the seven-day period ending on July 13 were running a version of the latest iOS 7 mobile operating system.
The figures compare positively to results from April, with the uptick from 87 percent representing gains of about one percent per month.
The boost in iOS 7 adoption came at the expense of devices running Apple's last-generation iOS 6, the share of which dropped from 11 percent to 9 percent. As with April's results, iOS versions equal to or older than iOS 5 accounted for two percent of total devices in use.
While iOS 7's adoption rate has slowed since December, which saw 78 percent of active iPhones, iPads and iPods using the "flattened" OS, any growth is impressive considering the company is scheduled to release the next-generation iOS 8 this fall.
The updated OS comes with a number of improvements as well as new additions like smart home support via HomeKit, fitness framework HealthKit and integrated Health app, open APIs, app extensions and continuity features that support high-level interaction with Apple's upcoming OS X 10.10 Yosemite.
Apple is expected to debut iOS 8 alongside a redesigned iPhone lineup sometime in September with bigger 4.7-inch and 5.5-inch form factor handsets. According to KGI analyst Ming-Chi Kuo, the larger 5.5-inch version may not be ready to launch with the 4.7-inch variant due to complications with in-cell touch panels and the smartphones' metal casing.