Apple has blocked a PC emulator app, UTM, from being available in the iOS App Store and third-party app stores, citing a rule that prohibits certain types of emulators. The app's developers claim that Apple is also blocking the app from being listed in third-party app stores in the EU. The rejection is based on the app's violation of rule 4.7, which covers game emulators and other types of apps. The app will still be available through manual installation via Xcode.