updated 05:44 pm EST, Wed January 15, 2014
Supports Chromecast, but currently acts as little more than a catalog
In an odd move, Google has release an iOS app for its Google Play movies and TV offerings, but limited it to streaming already-purchased movies and TV shows. The application also supports the company's Chromecast TV device, finally bringing a way for iPhone users to stream purchased content from the phone to the device -- but does not allow users to purchase or rent content from within the app.
There are other restrictions as well: currently streaming can only occur over Wi-Fi. When playing purchased content on the iPhone, it will only appear in standard definition (it will, however, stream in HD to the Chromecast). TV shows and general support are only available in the US, the UK, and Japan. Users won't be able to save content for offline viewing. There are no "info cards" that normally appear when a movie is paused, relating relevant trivia to the title.
The biggest hurdle is the lack of purchasing ability. Users must employ alternate means -- Android devices or the web -- to actually buy or rent content. The authorized content then shows up in the iOS app as available for streaming. While some of the limited abilities may be restored with future updates, Google is unlikely to ever allow direct purchases -- as it would then have to pay Apple its 30 percent distribution cut.
Google had previously released iOS versions of a Google Play Music app that similarly only supported streaming subscriptions (and its free "cloud locker,") and a Google Play Books app that similarly barred direct purchases. In the new app, AirPlay is not supported, so streaming cannot occur from device to device (barring the Chromecast, which uses its own "push" system of streaming).