Google announced the ability for guests to case content to your screen without signing onto your WiFi. The only requirement is for the Android device must be located in the same room as the Chromecast. o enable guest mode, simply go to the Chromecast app on your Android device and select “Devices”. Choose your Chromecast then tap “Guest Mode” and check “On”. Once you do the latest update to your app, you should have this feature and see the below message.