I spent some time on the site (though I wasn’t able register), and the service appears to be based primarily on an open source WebRTC media server called Kurento Media Server. I have a good bit of experience with scaling Kurento, and I assume the user management side of things is just something out-of-the-box like Django, et al.
As I said, I don’t have an account so I can’t see the full featurelist, but my point is: this shouldn’t be an overly complex service to build since most of the core features are encapsulated in pre-existing open source projects. I’d be interested in creating a resilient version of it (with maybe a $1 or $3 plan for heavy usage?) if anyone else wants to team up.
My core skillset is with scaling web services, so if anyone else is up to the task, I’d probably benefit most from devs with frontend experience or generalists/full-stack developers. Kurento is written in Java, so I’m assuming we’d need to write a Java plugin to convert the WebRTC data channel into something that a SIP backend can utilize (this might be easier than I am thinking, in fact, considering Twilio and the like exist and make these srt of integrations pretty straightforward).
Anyone else with dev skills please respond here; if I get enough interest, I’ll start an org on Github and we can team up from there!