Apple today released iOS 16.4 beta 4 for registered developers, including a new device thumbnail view for the warranty page, a revamped splash screen for Apple Books, and code-level references to “realityOS” – the alleged operating system set to power Apple’s long-rumored Reality Pro AR/VR headset.

The public release of iOS 16.4 will pack a number of added features overall, including new emojis, support for faster 5G speeds, and the resurrection of the page curl animation in the Books app.

The latest beta of iOS 16.4 replaces the stale 2D glyphs in the Warranty page of the Settings app with polished 3D renderings of products. Take a look:

The fourth beta of iOS 16.4 also contains a moderately revamped welcome screen for the Apple Books app. featuring a more streamlined layout. Here is a look at the new design:

Hidden in the source code of iOS 16.4 beta 4, developers on GitHub uncovered direct reference to “realityOS” and “Reality Simulator”, which are rumored to be the key software platforms supporting Apple’s unreleased mixed reality headset. Snapshots of this source code were shared by Twitter user @aaronp613:

Well-known iOS developer and resident source code sleuth Steve Moser, also took to Twitter, confirming that “PLATFORM_WOLF” is Apple’s internal codename for realityOS:

Evidence of this source code suggests the debut of Apple’s AR/VR headset could be imminent. Apple registered the trademark for “RealityOS” as far back as May 2022, under a coverup company called Realityo Systems LLC, according to Vox Media manager Parker Ortolani on Substack.

Last week’s beta featured key references to Apple’s long-rumored Apple Music service, Apple Music Classical, which has now been confirmed will launch on iPhone devices beginning March 28.

Users can install the update by visiting Settings > General > Software Update >Download and Install. A public version of today’s beta is expected later this week. Apple also released beta updates across the following platforms: 

• iPadOS 16.4 beta 4
• tvOS 16.4 beta 4
• watchOS 9.4 beta 4
• macOS Ventura 13.3 beta 4

We will keep this article updated with any additional changes that we find in the latest iOS 16.4 beta.