Night Shift

iOS 9.3 has introduced night shift feature for iPhones, which automatically tints our screen to warmer colors(less blue light) at nighttime, so that we don’t have to change the setting by our own for nighttime(like for reading at night time).

Night shift mode is optional and can be changed by
setting > display and brightness > blue reduction (with a slider) to control its  orange or blue look and also to adjust schedule of night time.

It helps to feel less stressed and relaxed at night .
It automatically adjusts display color in daytime and screen color and shifts it back to normal at daytime automatically.

Multi-user user support

iOS 9.3 release notes is the first sign of multi-user support.

Multi-user support helps multiple users to access their data on one iPad(no need of different iPad for different users). Users can make their personal login account and can access their personal data. It is mostly used in schools or colleges where people can’t afford different iPads for each student.
It is basically made for educational purpose.

Apple Notes password protected

This is an another good feature provided by iOS 9.3 to secure our notes from intruders. We can secure any kind of personal data(such as financial details, medical info or website logins) on our device. Apple Notes uses a single password to secure our note or if we have an iPhone or iPad with Touch ID, locked notes can be opened by our fingerprints.