If I create an app that will be installed on different devices (Windows, Android, Apple).
Different devices will be connected to Internet via different ISPs. Mostly devices will have changing dynamic IP address.
In this situation will it be possible for one client to find and communicate with all unknown devices connected to Internet and app installed. Like is it possible for one client to broadcast data to all other clients.
Is this potentially possible WITHOUT USING ANY CENTRAL SERVER for client to find ALL other clients?