For those who don't know, Phoenix Live View introduced Live View native, a framework where you can build mobile apps straight from a server view, everything gets synchronized live like Live View on the web. For the people who don't know what Phoenix Live View is, I encourage you to check it out, it's a great piece of tech.
I'm releasing now a tech preview of a Flutter client, you could build a mobile & desktop app using the exact same backend code as the web and just change the view, every diff is getting replicated live over a websocket, same as a Live View web client.
https://github.com/alex-min/live_view_native_flutter_client
I have a video demo of a simple counter being synced between the web, mobile and desktop on github, this demonstrates the concept clearly.