[Xorathena]

What audio system does this use?

Is it E2EE directly between you and the other person?

The website doesn't say much before you click the Start button. Everything has tradeoffs, and implementation details matter.

[imhoguy]

I have no means to check this page on my mobile now, but if it was me making it I would have used WebRTC, plus some backend to pair random peers. I think E2EE can be implemented on the stream.