Hello
I am an expert of webrtc, As you can see my profile, I have many experiences in webrtc and its plateforms such as opentok, sinch, quickblox, ... and so on
Hello
You need a what app like app well I have build one chatting app with all the options like chat files send picture video but calling features need to take a permission from the regulatory
If you want I can show the app which I build I can do that for you as well
Do message me
Thanks
Akram