An ESP32, able to open a hotspot and host an HTTPS server with secure websockets. Changes on any connected device will be reflected on all other devices, in real time.
On startup, the ESP32 will open a WiFi hotspot with desired credentials, and starts a DNS server to resolve a custom domain name (home.com), then hosts an HTTPS server with websocket secure (WSS).
Upon a device connection to the custom domain, contents of the HTML page will be served, after that a secure websocket connection will be opened, with the device asking for up-to-date information from the server. Exchange of data will be possible in real time.