A year removed from its bug-plagued launch, Apple's iOS 8 now is running nearly nine out of every 10 Apple mobile devices.
That's just in time for it to start giving way to the next version of the software that powers iPhones and iPads, iOS 9, which makes its debut Wednesday.
In what is likely its high-water mark, iOS 8 has scored an adoption rate of 87 percent, according to stats that Apple shared Tuesday via its App Store Distribution page. The 87 percent figure includes all the iPhones, iPads and iPod Touches that visited Apple's App Store on Monday, September 14. That's up from the and the .
The iOS 8 software was initially besieged by bugs that caused Apple in the latter months of 2014 to issue one fix-focused update after another. That's a problem the company needs to avoid with iOS 9 if it expects its new mobile software to score with users and to avoid a new round of complaints.
Where the earliest updates to iOS 8 often seemed heavy on bug fixes, subsequent releases were more notable for the new features they delivered. In June, for instance,, the company's attempt to compete in the growing music-streaming market.
Now the spotlight turns to, which Apple says will pack improvements to the voice-activated Siri digital assistant, the Maps app, the Notes app and the search feature. It also promises better battery life with a new low-power mode that turns off certain bells and whistles. And a new split-screen feature lets you run two apps side by side, but only if you're using the the iPad Air 2 or the new, big-screened iPad Pro.
In July, Apple pushed out, which gave general users a chance to test and troubleshoot the new software, whereas in the past only developers were given access to the prerelease iOS betas. The more people who can run software through its paces, the greater the chance that bugs can be uncovered before that software becomes available to everyone. (Apple actually .)
The stats released Tuesday by Apple also show an 11 percent adoption rate for iOS 7, down from 13 percent more than a month ago. That leaves just 2 percent for older versions, a number that's remained the same for several months. Older iOS devices aren't capable of running the latest versions, so they remain stuck at a certain point, unable to upgrade.
Meanwhile, iOS 8's adoption was pegged at 91 percent on September 14 by mobile analytics firm Mixpanel, which bases its figures on mobile app usage. Fellow mobile analytics firm Fiksu gave iOS 8 an 87.1 adoption rate as of Monday, in line with Apple's analysis.
Now the game begins anew as we see how iOS 9 fares over the coming days, weeks and months.