How to Auto-install future purchases
Go to Settings
If you want to download tvOS versions of apps to your Apple TV when you purchase their iOS versions on your iPhone, iPad, or iPod touch, without having to manually download them, go to Settings > Apps on your Apple TV.
The first setting on that page is “Automatically Update Apps.” By turning this on, you won’t need to manually check for updates, helping you to ensure that all your tvOS apps are always on the latest version.
Highlight “Automatically Install Apps.” By default, this feature – which allows tvOS versions of your iOS app purchases to be automatically installed on your Apple TV – is turned off. Click the trackpad to enable it.
Enter your password
You need to sign in to your Apple ID in order to enable automatic downloads, so enter your password — using either the keyboard or by holding the Siri button and spelling it out — and then choose OK.
Install new iOS apps
Before you install any new app on your iOS device, keep an eye out for the words “Offers Apple TV App” below the screenshots on its App Store page. Click Get or the price button (if it’s a paid-for app) and install it.
Auto-install on tvOS
As the app gets on with the task of installing on your iOS device, the tvOS version will automatically install on your Apple TV too, provided that you are signed in to the same Apple ID on both devices, of course.