Microsoft is expanding its Project xCloud service to the iPhone today. The software giant is launching a beta of xCloud through Apple’s TestFlight service, allowing xCloud testers to try the service on an iPhone or iPad. It’s the first time we’ve seen a cloud game streaming service appear on iOS since the days of OnLive — and OnLive’s iOS app wound up in limbo when Apple didn’t approve it. Google’s Stadia and Nvidia’s GeForce Now are still not available on Apple’s devices, either, and neither company has been able to tell us when that might change.

Microsoft apparently needed to make some tweaks to appease Apple, though. “To comply with App Store policies, the preview experience on iOS may look and feel different for those who have been testing on Android,” explains Microsoft’s Larry Hryb in a blog post.

Apple’s policies, which Microsoft doesn’t reveal or explain, mean that only a single title will work with iOS devices. Halo: The Master Chief Collection will be available to the 10,000 testers whom Microsoft says it’s inviting to the preview. The app is also limited to xCloud, and does not include the Xbox Game Streaming feature that streams games from an Xbox console.

It’s not clear what Apple’s limits are, or why the iPhone maker keeps restricting cloud-based game streaming services from launching on its iOS devices. Google launched its Stadia service with a basic iOS app that doesn’t support streaming, and Microsoft seems to be pushing ahead with testing in hopes that Apple will finally approve these types of apps. It took nearly a year for Apple to approve Valve’s Steam Link app, even though it primarily streams games from your home PC.

Similar apps like Remotr and Rainway have also made it onto the App Store, but not curated streaming services. The closest is Blade’s iOS app for Shadow, which lets you access a gaming PC that lives in a server farm, but which also does not include a catalog of games itself.

If you’re lucky enough to receive an invite for the xCloud iOS testing, it will appear in your email inbox. You’ll need to register (or re-register) using this link and select “iOS” as your phone make or model for Microsoft to select you as an iOS tester. Microsoft says it will be swapping out participants due to the testing limit restrictions, and hopefully we’ll see some more games added if Apple allows.

Update, 1:38 PM ET: Added more context about OnLive, Shadow, Remotr, Rainway.