Twenty-four hours after the release of iOS 9 in September, it was estimated that 12% of devices had the update installed, slightly less than after launching iOS 8 last year, during the same period time.
Now, three weeks after the public release of iOS 9, Apple has published its own numbers, which were obtained using the number of people applying from iOS to App Store before October 5, 2015. Based on these numbers, Apple reported that 57% of devices currently have firmware iOS 9 installed. If we compare this figure with last year's figure, then during the same period of time iOS 8 was installed on 47% of devices.
Today iOS 8 is installed on 33% of devices, while older versions of the operating system from Apple are present on 10% of devices.