Apple's newest mobile software has seen a small gain in adoption over the past couple of weeks.
As of November 2, iOS 9 was gracing 66 percent of all iOS devices, a group that includes iPhones, iPads and iPod Touches, according to Apple's App Store Distribution page. That's up from 61 percent on October 19, a decent gain following a slight slowdown in .
The adoption rate of a new version of iOS reflects both how many people are buying new Apple devices and how many are upgrading from a previous version. Apple needs to keep its mobile software fresh with new features and bug fixes to compete with Android for smartphone buyers and to keep current iOS users happy.
The small pickup in the adoption rate follows the release of, which added new emojis, including a taco, hot dog, champagne and a unicorn. The Live Photos feature was repaired so the camera stops recording if it senses that the iPhone has been lowered. The latest update also fixed bugs in such features as CarPlay, the app switcher, the calendar, Game Center, app updates and email.
Launched on September 16, iOS 9 within four days had landed on, which Apple proclaimed as the . But that rate slowed as the company was forced to battle several bugs, leading to the release of version 9.0.1 and version 9.0.2 six days later.
A release number like 9.1 also typically signals a major update versus a number like 9.0.2, which points to a more minor update. A certain percentage of users may have been waiting for 9.1 to debut before updating their iPhones and iPads.
Apple measures iOS adoption based on the number of devices that visit the Apple Store, with the latest stats tracking visits made on November 2. Third-party analytics firm Mixpanel, which bases its data on mobile-app usage, put iOS 9 at an adoption level of 72 percent as of Monday. Fellow analytics firm Fiksui came much closer to Apple, saying iOS 9 was at 65 percent.
Apple did not immediately respond to CNET's request for comment.