iOS 9.3

One of the key new features previewed in last week's iOS 9.3 beta is Night Shift. The basic premise is that blocking blue wavelengths of light after the sun has set improves sleep. This blue light is normally generated by iPhone, iPad and other mobile device screens, simulating sunlight. By reading iBooks in the evening or playing video games late into the night, circadian rhythms are disrupted. Night Shift addresses this problem, however it's by no means the first software to tackle the issue.

The week in iPhone news was exciting for Apple fans looking forward to future devices and firmware. A surprise release of iOS 9.3 beta to developers revealed significant feature improvements in the pipeline. Details on the upcoming 4-inch iPhone slated for release early this year also surfaced, along with a new moniker for the device. Changes are also on the way to iTunes Radio and the iAd platform. Here are five highlights from the top Apple news of the week:

Apple caught everyone off guard on Monday by releasing the first iOS 9.3 beta filled with tons of new features. iOS 9.3 includes more than your typical amount of major upgrades normally found in a minor release. The update adds a new Touch ID security option for the Notes app, a Night Shift mode, new CarPlay features and more.