It's a web app. I'm developing it as a PWA for easy installation on mobile devices. No app or app store required. Installation is like adding a bookmark.

https://www.bitcot.com/how-to-install-a-pwa-to-your-device/

Since it's a web app, I don't see why it couldn't be installed on any TV with a built-in web browser.

How are you getting access to the YouTube API in a way that's available to 3P developers?