As of September 21 (five days after the release of iOS 8), Apple reported that 46 percent of its iPhone and iPad users had upgraded to the newest version of its mobile operating system. The firm added that 49 percent were using iOS 7, and 5 percent were using earlier versions.
Some in the mobile development industry have criticized Apple because users aren't adopting iOS 8 as quickly as they did earlier versions of the operating system. Still, others point out iOS 8's adoption rate still far exceeds that of any Android update.
A separate but related report from mobile app performance management vendor Crittercism finds that iOS 8's crash rate is 78 percent higher than iOS 7's. Older devices seem to be particularly prone to crashes.