Google Play Movies & TV lets iDevice users watch movies and shows purchased through Google Play via Wi-Fi.
It also supports Chromecast, so if you own one of Google's $35 streaming sticks you have another way to beam content to your TV.
But note that you can’t buy movies or shows from the app because Apple doesn’t permit software that sells its own content on the App Store. Instead, you have to purchase content from a web browser. Also, the app has no offline support.