I searched for an answer to my question but I didn't find a pleasing result, so here is my question in detail:
I'm currently developing an app for android and ios which should be able to perform "calls", similar to how skype or microsoft teams do. So I need a way to detect if one receives a call even if the app isnt running and then display an overlay or at least a notification from which I can accept the call and start the app.
Is there a tutorial on how to achieve this? I can't imagine being the first one struggeling with this...
Thanks in advance