Registered developers can download the new beta version of iOS 12.1 directly from the Apple Developer Center once the correct configuration profile has been installed in the Developer Center.
iOS 12.1 includes some new features that Apple has promised to come with the new iPhone XS and XS Max devices. The beta version adds support for the eSIM, a digital SIM card that enables you to activate a mobile plan from a mobile operator without having to use a physical SIM card.
Carriers need to implement support for eSIM, which is likely to happen after the introduction of iOS 12.1. In the US, AT & T, Verizon and T-Mobile will support eSIM.
The iOS 12.1 update includes new real-time depth control software that lets you adjust the depth of field of your portrait mode photos before capturing them. At the moment, the depth control in iOS 12 is only available for editing after recording.
If you tap the "F" icon at the top of the screen while taking a picture, use the Depth setting to adjust the amount of background blur in an image.
In addition to these iPhone XS and XS Max features, iOS 12.1 reintroduces the group FaceTime feature, which was removed from iOS 12 during the beta testing phase. Group FaceTime was present in many early betas but was eventually removed as Apple needed more time to test it.
Group FaceTime is designed to allow iPhone and Mac users to simultaneously make video and audio chats for up to 32 participants, including new camera effects.
The update adds more than 70 new emoji to iPhones and iPads, with options like red hair, gray hair, curly hair, cold face, party face, face with heart, mango, kangaroo, peacock, lobster, cupcake and more.
As for the fixes, iOS 12.1 fixes a loading issue that may cause iPhone and iPad models with iOS 12 not to load when connected to a Lightning cable while the screen is off and causing an error, iPhone XS and XS Max models have favored 2.4GHz Wi-Fi networks to 5GHz networks, resulting in slower Wi-Fi speeds. Both bugs have also been fixed in the iOS 12.0.1 update released yesterday.
If more additional features are found in the third iOS 12.1 beta, we will update this post with details.
To update: Apple has also released a new beta version of iOS 12.1 for its public beta test group.