Threema video call support

[monty241]

Is your proposal related to a problem?

Currently, cal.com supports only element (https://element.io) as a video call solution under European control. However, element has a quite steep pricing, starting off at a minimum of 50 users at EUR 5 each per month, when just a few users are needed.

Threema (https://threema.ch) is a Swiss-based solution that is used for approximately 10 million seats mostly in the German-speaking countries (Germany, Austria, Switzerland), which bundles chat, voice call and video call.

It is considerably cheaper since there is no minimum number of seats.

An integration of video calls with Threema would make it easier to ensure content of video calls are not routed through a US-controlled data center.

Describe the solution you'd like

I would like the option to also use Threema besides Element as a video call method from cal.com.

Describe alternatives you've considered

Alternatives (so far found, the app store does not list whether the company hosting it is under US control):

• Element: starts of at EUR 250 / month. Meets regulatory needs.
• Jitsi: owned by 8x8, a US company. The open source version might have hosting parties in EU under EU law.

Bounty

Willing to put a EUR 1000 bounty on this functionality.