Starting today, the Apple TV app is now available for Android TV devices. Nvidia broke the news that the Apple TV app was available for its Shield TV today, but neglected to mention that it was available generally to all Android TV devices.
Google has now confirmed that the Apple TV app is available to all Android TV devices. We can confirm that a quick search in the Play Store on an Android TV device will surface the Apple TV app and is available to install. You just need to have an Android TV device with Android 8.0 or higher and is not an operator-tier device.