First, ensure that your Chromecast has been set up to cast from the app. Get more info about this here.
To cast from an iPhone or iPad:
- When the video is playing, tap the Chromecast icon in the upper right hand corner.
- Select the device to which you would like to cast.
- The app will begin casting.
To stop casting from an iPhone or iPad:
- While the show is playing, tap the Chromecast icon.
- Select Disconnect to end the cast.