Today's iOS build, 15F5049c, resolves issues that have to do with AirPlay, Keychain, and Music.
Apple has released iOS 11.4 beta 2 to developers for testing. According to 9to5Mac, the iOS 11.4 public beta 1 highlights Messages in Cloud, a feature that synchronizes the user's messages in all of his or her owned Apple devices.
iOS 11.4 and tvOS 11.4 once more include support for AirPlay 2, Apple's upcoming wireless streaming protocol that supports features like multi-room audio.
When the user removes a message in a conversation using one Apple device, the same message will also be deleted other device platforms, like the iPhone, iPad, and MacBook. Like AirPlay, the last feature has been promised for iOS 11 for some time but conspicuously absent. Stereo support for two HomePods is also included but won't work until Apple launches new HomePod firmware. It would seem that this round of updates is meant to wrap up all of Apple's promises for iOS 11 and its counterparts.
AppleInsider is now testing out the new betas to find out what changes have been included, if any.