Those who have joined the Xbox Insider program have been able to enjoy playing Xbox games wherever they are with both Xbox Console Streaming (whereby you can stream your own games) and xCloud (stream any of the games included in the service) since last autumn, although only for Android units. So far. Yesterday, however, that changed and Larry "Major Nelson" Hryb announced that Microsoft has now started testing out xCloud for iOS as well in Canada, UK and the USA.
There is a slight catch though, and only 10,000 users are allowed in the first round, and Major Nelson writes that "we saw a LOT of interest in the Project xCloud Limited iOS TestFlight Preview today and we've already hit our initial capacity". It should also be noted that the only game available so far is Halo: The Master Chief Collection.
If you would like to participate in the xCloud tests, head over this way, where you'll find instructions on what you should do to try and get in for the next round.