Apple previews iOS 11.3: Update will let you turn off iPhone throttling, see all the changes here
2. Users will have a toggle for enabling/disabling the power management feature that can affect maximum performance on iPhones. The feature can be located in the Battery subsection of the Settings menu. Power management is currently present on members of the iPhone 6, 6S, SE, and 7-gen devices.
3. ARKit 1.5 will be introduced to developers. ARKit will be able to place virtual objects on walls, doors, and other vertical surfaces. Additionally, it will be able to map irregularly shaped surfaces in a more accurate manner. The view of the real world through the camera will get 50% greater resolution and support for auto-focus will be added.
4. A new Health Records feature will be added to Health app. It will bring together info from hospitals, clinics, and the app itself to organize and provide quick an organized access to the medical data. The service will be encrypted and passcode-protected.
5. 4 new Animoji characters will be added - a lion, bear, dragon, and skull.
6. Music videos are coming to Apple Music.
7. Apple News will get improved Top Stories and Video group feature in "For You" section
8. Business Chat feature will be added as a beta to Messages. It will allow users to communicate with businesses more easily.
9. Support for Advanced Mobile Location (AML) to automatically send a user’s current location when making a call to emergency services in countries where AML is supported.
10. HomeKit software authentication allows developers to add HomeKit support to existing accessories.