threema

Install command: 
brew install --cask threema

Name: Threema

End-to-end encrypted instant messaging application

https://threema.ch/

Cask JSON API: /api/cask/threema.json

Cask code: threema.rb on GitHub

Current version: 1.2.48

Requirements: macOS >= 10.15

Analytics:

Installs (30 days)
threema 20
Installs (90 days)
threema 96
Installs (365 days)
threema 567