It will come standard on the new iPhone XS, iPhone XS Max and iPhone XR.
CNN Tech recommends waiting a week or more to install it on your phone to avoid any undiscovered bugs, and to back up your phone before upgrading.
The new features are:
1. Screen Time tool
The new feature called Screen Time is located in Settings. It tallies how much time you spend on your phone. You can see detailed breakdowns, including how often you pick up your device, and set limitations for certain types of apps. It’s a great feature for parents.
The "memoji," an animated emoji cartoon, can be customized to look like anyone. Apple also added four new animoji characters -- a ghost, koala, tiger and T. rex -- with wink and tongue detection.
The animoji features only work on the X lines of iPhones because they require the face-detection cameras.
Apple also introduced new camera features such as stickers, but only if you're using the camera directly from the Messages app.
3. An app for measuring
The app called Measure lets you measure things, including surfaces and people.
4. A more useful Siri
The voice assistant has new tricks, including the ability to turn on the flashlight. CNN Tech reports the real improvement is the Shortcuts feature in Settings.
You can record your own Siri commands based on common tasks or recommendations from app usage. You can add commands that start a voice memo recording when you trigger Siri and say "Captain's Log," or one that Googles your name when you say "Google me."
The built-in options in Settings are limited, but Apple is going to release a stand-alone Shortcuts app that will let you build more complex custom commands.
5. The little things
Apple News is redesigned to include a Channels tab for cruising through your top publications. It features two-factor authentication security codes, which offer better password protection, CNN Tech reports.
It also includes new pops-up in auto-fill suggestions and when you call 911, your location is sent directly to emergency responders.