We don't believe in proprietary solutions. That's why you don't need to install anything to use Okomo.
For audio or video calls, as well as to share the screen, we use WebRTC. WebRTC (Web-Realtime Communication) is a technology standard for real-time communication through a browser. In other words, WebRTC allows you to make a call directly from your browser. The data is exchanged directly (and not via server) and is end-to-end encrypted.
See this link for the latest information on WebRTC support in browsers.
The only disadvantage of WebRTC is that it is somewhat resource intensive. That's why it's possible that your device's fans will turn on during a call. You can also manually reduce the call quality to use fewer resources.