A notable uptick could be explained by the Apple Watch, which requires the iPhone 5 and later running iOS 8.2 and later. For those wondering, Apple measures active devices by monitoring iPhones, iPads and iPods that access the App Store.
Some seventeen percent of devices are still using iOS 7, as measured by the App Store on April 27, 2015, representing a two-point decrease from the nineteen percent of iOS 7 devices two weeks ago.
The stats likely indicate that the bulk of growth in terms of iOS 8 adoption rate over the past two weeks came from people who’ve upgraded from iOS 7 — again, likely in order to be able to use their brand new Apple Watch.
As you know, the Apple Watch as an iPhone companion requires the Apple Watch companion app, which in turn is compatible with iOS 8.2 and later.
So are you still on iOS 7 or upgraded to iOS 8 ?