How can I download an AndroidTV App to my Google device?

Press the HOME button on the remote control.
Select the Google Play Store on your device.

→ You will then be taken to Google's app store: Google Play, where you can browse for apps, and download and install them on your TV.
In the Google Play Store screen, use the navigation buttons of the TV remote control and select the Search icon.
Use the on-screen keyboard on the TV to search the name of the app that you want to install (as an example, we are showing you the Cooking Channel below).
Press the right arrow button on the remote control twice. The on-screen keyboard is displayed at the bottom of the screen.
From the search results, select the app that you wish to install. And then select Download.