With Screen Mirroring for Home Theater you can mirror your screen on any TV screen from Apple TV and Roku, and it's free! Using Screen Mirroring for Apple TV, it is possible to mirror any Apple TV screen, including the Apple TV 4K and Apple TV 4. For Apple TV the option is under Settings > Accounts > Apple ID. For Roku, go to the Home Screen, then click on your account name and scroll down to Settings > Devices. Select Apple TV from the list of devices, then scroll down to Settings > Stream to device. You can then select which TV you want to mirror and on which Apple TV. For Apple TV 4K and Apple TV 4, make sure you select the correct Apple TV version and scroll to the bottom of the page and click Stream.