Apple releases iOS 11.4 developer and public betas; all new apps must support iPhone X
A pair of features that were found in beta versions of iOS 11.3, but removed for the final version, appear in beta versions of iOS 11.4. These include AirPlay 2, which allows the same audio to play on two different HomePod smart speakers in different rooms. Messages on iCloud allows messages to be stored in the cloud, freeing up storage space on your iOS device. And when a message is deleted on one device, it will disappear from all of your iOS powered Apple products. The latest beta release also includes (PRODUCT)Red wallpaper for the Apple iPhone 8 and Apple iPhone 8 Plus. Those special variants were introduced on April 9th.
Also, Apple has announced that starting in July, all apps must be built using the iOS 11 SDK and support the screen on the Apple iPhone X. That means that an app must work with an aspect ratio of 18:9, the 1125 x 2436 resolution, and account for the notch on the top of the screen. Originally, Apple wanted this to be done by April, but has apparently extended the deadline by three months.