Today, Apple has released the final version of iOS 9.2.1 to the public. Since this is only a minor release, no major features changes were included in the release notes. As usual, references to bug fixes and improvements to performance and security are also in the notes for this release.
One possible bug that may well be fixed in this release is the battery indicator bug on the iPhone 6s and 6s Plus that we wrote about yesterday. That particular bug may take some time to actually see in the wild, as it requires switching time zones.
In releasing a public preview page for iOS 9.3, Apple may be opting to release features more gradually throughout the year. If that is the case, updates like iOS 9.2.1 would be reserved for bug fixes and small improvements that had accrued since the last point release. It’s unclear when the final version of iOS 9.3 will be released.
The update is available over-the-air in Settings > Software Update or by plugging your device into iTunes. If you’re lazy, since iOS 9 the operating system has begun prompting users to let the update install overnight, but that normally takes a day or two.