Apple has just made iOS 9.1 final release available to public. iOS 9.1 is third and major update for all compatible devices since the release of iOS 9 in September. With iOS 9.1 update, Apple brings 150 new emojis, Live Photos enhancements, improved multitasking performance and improved stability including CarPlay, Music, Safari, Photos and Search. iOS 9.1 fixes a number of issues which persisted in previous iOS 9 versions.
You can upgrade to iOS 9.1 using OTA updates on your device. To upgrade your iPhone, iPad or iPod touch to iOS 9.1 via OTA update, go to Settings > General > Software Update. Tap Download and Install to start the upgrade process. If you prefer, you can do a full restore via iTunes using iOS 9.1 IPSW. iOS 9.1 IPSW download links are below.
If you are jaiilbroken on iOS 9.0, 9.0.1 or 9.0.2, you should not upgrade to iOS 9.1 in order to preserve your jailbreak status. If your device is jailbroken on older iOS version (<9.0) and you wish to update it to iOS 9, you should download iOS 9.0.2 IPSW and do a restore via iTunes. After which, you can jailbreak your device using Pangu iOS 9 jailbreak. You have a short window of time to decide whether you want to upgrade to iOS 9 or stay on older version. Although an upgrade is recommended.