In brief: Apple has added support for unlisted apps to the App Store, making it easier for developers to directly share their apps with intended users instead of the general public. Such apps will not appear in any App Store category, search, or discovery section and can only be downloaded via a direct link.
Apple has announced that developers can now request to submit unlisted apps on the App Store. The feature, rolled out across all supported regions, should come in handy for when an app is meant to be used only within an organization, for research studies, special events, or as an employee resource or sales tool.
The support document explains that developers can request to have their existing (listed) and new apps hosted this way. Following Apple's approval, the app and all its future versions will be distributed under the "Unlisted App" method, allowing developers to share it with users via a direct link.
Unlisted apps sounds like it could be neat, but it looks like it has some big caveats. Also doesn't seem like my Individual developer account is authorized to request an unlisted link. Business-only?--- Steve Troughton-Smith (@stroughtonsmith) January 28, 2022
"Note: Once your app is approved, the distribution method cannot be changed." https://t.co/o34hB1v8VR
This new distribution method also works with Apple Business Manager and School Manager, however, switching to it will require creating a new app record. Secondly, an unlisted app candidate will also have to go through Apple's usual App Review process, and should therefore be ready for final distribution, as apps in pre-release or beta stage will be rejected.
A link will be generated once a new unlisted app is approved, while those already available on the App Store will use their current link. Since app access lies solely on having this link, Apple advises developers to deploy preventative measures against unauthorized use of their apps.