Next, and perhaps more importantly, you can use Chromecast Audio to create a multi-room system over WiFi similar to the likes of Sonos and others. As you might expect, you'll need one of the dongles in each room you plan to beam music to, but once they're in place, you can use the Chromecast app to group them. Once they're all connected together, simply cast the audio to your speakers just like you would to a single unit. To take advantage of the new features, update to the latest version of the Chromecast app on iTunes or Google Play.