https://www.cnet.com/news/apple-unblocks-googles-internal-apps-on-ios-devices-report-says/

The block came because Google sidestepped the App Store and took advantage of Apple's developer enterprise program, which is designed to let companies internally distribute apps, TechCrunch reported Wednesday.

In response to Wednesday's report, Google had said it's shutting down the Screenwise Meter app on iOS devices.