Today Apple released its second beta iOS 11.3 and tvOS 11.3 to developers. Registered developers can download new beta versions from the Apple Developer Center or over the air using the Software Update mechanism.
iOS 11.3
iOS 11.3 will be a major update with support for AirPlay 2, 4 new Animoji, battery health section, ARKit platform improvements, Health app and other changes.
The second beta iOS 11.3 finally added the ability to disable power management. In addition, a whole section has appeared in the Settings dedicated to the state of the device's battery. In addition, there are the same 4 new Animoji (lion, bear, skull and dragon) and many more minor changes. The Health app has changed a bit, App Store has updated file sizes, and the iBooks app is now called Books. Messages in iCloud are still not available, but this feature should appear in future beta versions.
Beta program members will also find the latest beta version available under Settings – General – Software Update.
tvOS 11.3
There won't be many changes in tvOS 11.3. The update is mainly aimed at fixing bugs and improving security. However, the new version still contains the 'Match Content' function, which automatically adjusts the frame rate to the content, automatic mode AirPlay, etc.
Apple promises to release the final versions of updates 'this spring', which means at least a few more beta versions await us. At the moment, the last public versions remain iOS 11.2.5 and macOS 10.13.3.
Note: Apple warns that users who are going to install iOS 11.3 beta 2 via iTunes will need to use iTunes 12.7.3. Face ID and other features may not work with older versions of the app.