A week after releasing the fourth beta versions of iOS 12.1, watchOS 5.1, and tvOS 12.1 to developers, Apple today rolled out the fifth developer betas for each operating system version. The new builds are now available to download from the Apple Developer Center or through an OTA (over-the-air) update.
In general, the latest builds do not seem to introduce major new feature additions, save for the minor changes. The fifth iOS 12.1 developer beta, in particular, bumps up the software's build number to 16B5089b from 16B5084a of the previous build.
Like in the fourth developer beta, support for Group FaceTime comes with the new build, allowing as many as 32 users to join in a similar video conference with complete access to Memoji on compatible iPhone devices. There's also a new set of 70 emoji and new code which enables support for horizontal Face ID, plus a fix for charging issues with the iPhone.
Meanwhile, the fifth developer beta for tvOS 12.1 bumps up its build number to 16J5602a, though there are no major changes except for general improvements and bug fixes. Finally, the latest beta for watchOS 5.1 carries the build number 16R5589c, with the main change being the addition of Group FaceTime call support and the ability to manage calls via audio until a user chooses to continue in video using an iPhone.
Before downloading the new builds, it's important to remember that these are unstable versions of the OS and may lead to potential data loss or other issues.