Google's Chromecast devices are small HDMI dongles that are powered through a USB connection or with the supplied power adapter.
To set up your Chromecast you have to register it with the Google Home App to let it join your WiFi, both methods are available at https://www.google.com/chromecast/setup/
You can then use Google's Chrome Browser to cast your entire screen or individual browser tabs from your PC/Mac: just select "Cast" in the Google Chrome Menu, select your Chromecast and what you would like to cast.
The Google support pages have all the details available.
Pros: relatively easy to set up through the app, platform independent solution as long as you run Google Chrome or use the Google Home App.
Cons: the stream is compressed severely, in our testing, picture quality was often not very satisfying and showed compression artifacts.
In case you have further questions, don't hesitate to contact the support team via the chat or support@walls.io!