Microsoft has extended its Project xCloud preview to iOS users, but there are some restrictions due to App Store policy.
Project xCloud preview is available for iOS users through the TestFlight program in the US, UK, and Canada.
Space is limited to 10,000 testers, and due to App Store policies, it does not include Xbox Console Streaming at this time. Only Project xCloud is being tested.
The only game available at present is Halo: The Master Chief Collection, again, due to App Store policy.
If you want to be included, invites will be sent on a first-come-first-served basis.
In order to participate in the Project xCloud limited iOS TestFlight preview, you will need to have a Microsoft account associated with your Xbox gamertag. Your iOS device must be running 13.0 or greater and also Bluetooth version 4.0.
You will also need a Bluetooth-enabled Xbox One Wireless Controller, and obviously you will need access to Wi-Fi or mobile data connection that supports 10Mbps-down bandwidth, similar to streaming video.