How to develop an application compatible with multiple smart TVs?

Cross platform smart TVs

Here is what I want to achieve:

  1. The user has a mobile application to control the TV interface (IOS and Android written in react native)
  2. The TV screen will display some text, videos, photos from a server based on user inputs (Chromecast, Roku, androidTV, appleTv, TizenTv,…)
  3. The TV can be controlled by multiple mobile devices and the mobile devices need to communicate between them (ex: the first phone select an image on the TV screen and the other phones must know which picture have been selected).

I know this can be achieved by using a chromecast but in order to reach more users I would like to make it work on other smart TVs.

I am new to the development on smart TVs and I don’t know what can be done at this moment.

Do you know if it’s possible to do it with only one codebase for multiple smart TVs ?

Do you know if it’s possible to make it work on chromecast and other TVs (ex: Apple TV) since they don’t work the same way ? (Apple TV host the application not chromecast)

How would you do for the communication between phones ? (peer to peer or is it possible via the smart TVs ?)