iOS 9.3 also lands with a number of bug fixes and new features.
A new feature, dubbed Night Shift, adjusts the device's light exposure based on the time of day. Using your iPhone or iPad's clock and geolocation, the light shifts towards a warmer end of the spectrum, making it easier for the user's eyes to adjust for sleep.
Notes has been updated, allowing individual scribbles to be protected with a passcode or Touch ID, the in-built fingerprint reader.
News and Health apps also see incremental updates.
If you haven't already been notified of the new software, you can get the update now through the Settings > General menu.
For privacy and security, change these iOS 9 settings right now