In need of a common app for all Smart TVs that occupies full screen on boot.
Is chrome browser supported by most or all Smart TVs, so that I can launch a chrome app onboot ?
Chrome browser is not a standard install on smart TV. Remember there is no "standard" for a smart TV. Manufacturers can decide to have the whole stack with their software.
And they control what appears on the store. I can't see any app Chrome or otherwise that would be gives control of any smart TV on boot, never mind let your app take control via Chrome