Earlier this May, valve released the Steam Link application to broadcast computer games to smartphones and tablets running Android. A large library of games from Steam became available for streaming on the mobile platform. Valve used to charge for a separate mobile device, however it appeared only to be conduit for their software. Now, the software has been ported to android and soon to be IOS devices.
To broadcast the games, you first need to bind the mobile device to the Steam client on the computer. Then, owners of TVs with Android TV will be able to run games through the installed Steam Link application. Afterwards, users can connect any compatible controller to their device to stream their games.
At this point, the Steam Link for Android is in beta testing, so there may be errors and flaws.