Google has an example application in the webrtc repository, although I don't think it was created using Xcode.
git clone https://chromium.googlesource.com/external/webrtc
In this repo you can find it in: webrtc/examples/objc/AppRTCDemo/
See assembly instructions for READMEc webrtc/talk/app/webrtc/objc/README.
- Node.js/Chromium runtime, NW.js Electron.