Update: iOS 9 has updated to iOS 9.3, with the current version, iOS 9.3.3, the last stopgap before iOS 10. Here's everything you need to know about the recent iPhone and iPad interface changes.
iOS 9 launched back in September of last year and it was instantly better than iOS 8, thanks to new features that make the iPhone and iPad software easier to use.
Siri is smarter, Apple Maps has transit directions and the notifications drop-down menu is now sorted chronologically (and, thus, logically). Best of all, every device that works with iOS 8 works with iOS 9.
It improved even further in March with the rollout of iOS 9.3. The new software rolled out alongside the smaller iPad Pro 9.7 and even tinier 4-inch iPhone SE. iOS 9.3.3 is the latest version in that release.
iPads benefit the most from this current operating system update. New iPad multitasking functionality, especially for the iPad Air 2 and iPad Pro, finally fulfills the tablet's promise of productivity on the go.
While iOS 9 and even iOS 9.3.3 lack key Android N features, there's a lot to like about it on the iPad and phones like iPhone 6S and iPhone 6S Plus. It's enough to tide us over until iOS 10.
Check out our collection of guides on how to use iOS 9
iOS 9.3 update
iOS 9.3 is Apple's first major update with exciting new features to highlight, so you'll actually really want to update to the newest software version. It's now up to iOS 9.3.3.
This contrasts with what we've seen before: iOS 9.1 added new emojis, iOS 9.2 tweaked Apple Music and Apple News and iOS 9.2.1 just fixed bugs. Nothing exciting. iOS 9.3 is different.
Specifically, the new software debuts Night Shift, which automatically tints your iPhone and iPad with warmer colors. Bright blue light can keep you up at night, studies have shown.
Night Shift uses the time and geolocation to determine the sunset and the display returns to normal in the morning. It's a feature we've seen from third-party apps like f.lux on Mac, but a first directly from Apple.
Interested? Here's how to download iOS 9.3 right now
Educators wielding iPads can dive into a new classroom app and multi-student login. Passing an iPad around the class can let students save their work to individual profiles and pick up where they left off.
Beyond that, Notes can be locked behind Touch ID for additional security, and the Apple News and Apple Health apps have been tweaked with minor design and content changes.
Specifically for the US, Verizon customers without a strong signal can now switch on Wi-Fi calling, just in case the usually reliable carrier doesn't have a good signal while you're in the range of a router.
iOS 9.3.1, iOS 9.3.2 and iOS 9.3.3 all took care of behind-the-scenes issues with iOS 9.3. One front-facing feature change to the latest software is the ability to run Night Shift and Low-Power mode at the same time.
iOS 9.1
The first small update Apple brought to its mobile operating system was iOS 9.1. Its headline feature? 150 new emoji, brought about through its support of Unicode 8, so you can more easily express the fact that you're painting your nails or playing at detective.
The update also added a trio of new wallpapers, but the most significant additions are the least visible ones, as iOS 9.1 fixes a number of bugs, improves general stability and boosts the performance of multitasking, the Calendar, Game Center and Mail.
iOS 9 1970 glitch
Don't reset your iPhone date back to January 1, 1970. Doing so can brick your iPhone upon resetting it, requiring a visit to the Apple Store for some major surgery.
It's an iOS glitch affects all newer iPhones running iOS 9, and it's thought to happen because the phone recognizes this date as a negative time