Yes, that's the first Google result, and they suggested building your own using socket.io -- read my article, if you haven't already (but some of their other _stack_ suggestions are decent).
Their ready-made signaling server suggestions are complete garbage (Signalmaster is buggy and incorrect).
I've not found signalling to be complex at all. You're just forwarding messages from one user to another. The server in the middle doesn't need to know anything other than to whom the messages go.
The one thing that is not handled in any material I've ever read on WebRTC: how to sequence more-than-two users joining a session at the same time, and how to recover from errors and stalled connection attempts (where the latter is a significant impediment to the former).
https://www.html5rocks.com/en/tutorials/webrtc/infrastructur... before implementing that one?