OpenTok is a Video Call API platform (js) using WebRTC.
(https://tokbox.com/)
You can try for a month for free.
(You need to put a valid API Key and API Secret in OpenTok_SDK site properties to work)
In this module I build a few functions and REST services for:
You can build your own video call aplication with some components that it is included in an Example App:
More info about SDK and REST: https://tokbox.com/developer/