How to download apps on your Apple TV device through the App Store

You can download apps on your Apple TV device using the Apple App Store, and customize your Apple TV home screen.

How to close apps on your Apple TV, so nothing is slowing your system down in the background

You can only close apps on the Apple TV 4K and Apple TV HD, as other models don't run apps in the same way.
Macworld

Apple TV tweaks: The 8 settings you should change ASAP

Compared to the iPhone and its complex functions, the Apple TV 4K is a relatively simple device. You’ve got a simple Home Screen with large icons, a few menus ...