Apple has just unveiled all the features it's adding to iOS 9.3, and though the headliner might be the beginnings of multiple user support (at least for students), there's another feature that's going to please everybody else. It's called "Night Shift," and it subtly shifts the color temperature of the display based on the time and location of your iPhone or iPad. The point is to have the screen blast less blue light into your eyeballs, which is one of the things researchers believe can cause sleep problems if you use a screen too late in the evening.
Amazon added a similar feature to its Fire tablets last month, and actually, shifting the color temperature of your display has been a popular feature on a lot of gadgets. A popular tool for the Mac, called F.lux, is well-known and oft-used around these parts, but there are other utilities that do similar things. F.lux actually created an iOS version of the app, but last November Apple shut the app down for using private APIs (it also needed to be sideloaded to work). When Apple shut F.lux for iOS down, many speculated that it would become a baked-in feature for iOS. Good guess.
Alongside Night Shift, Apple is also adding private notes, which let you set some notes as hidden unless you open them with Touch ID. Apple News gains better news recommendations in For You and can also be viewed in landscape. CarPlay is getting some improvements and there's also a new dashboard in the Health app. Those all go alongside the slew of education features that Apple is baking into the platform (presumably to fend off ChromeOS' success there).
iOS 9.3 is a public beta, and you can sign up for it here. Take note, however, it's usually not a good idea for most people to install betas on their main devices.