Apple today seeded the first beta of an upcoming iOS 11.4 update to developers, a little under a week after releasing iOS 11.3, an update that introduced a wide range of new features like Battery Health for monitoring the status of your iPhone's battery, Business Chat in Messages, ARKit 1.5 with augmented reality improvements, new Animoji on iPhone X, Health Records from participating medical providers, and more.
Registered developers can download the new iOS 11.4 beta from Apple's Developer Center or over-the-air once the proper configuration profile has been installed from the Developer Center. It appears there's currently a bug preventing the beta profile from being downloaded, but it should be addressed soon.
It's not yet clear what new features will be included in the iOS 11.4 beta aside from the new ClassKit framework Apple introduced at its March event, but we are waiting on several features to be added to iOS 11, including iCloud Messages and AirPlay 2, functionality that has popped up in previous betas and then disappeared before release.
What's new in iOS 11.4 Beta 1: Messages on iCloud is present in the iOS 11.4 beta after being removed from iOS 11.3 ahead of its release, as are AirPlay 2 features. Apple TV devices are once again listed in the Home app, an AirPlay 2 option.
Stereo support for the HomePod is included, but the feature doesn't work properly as it requires unreleased HomePod software.
Source: macrumors