Description from extension meta
Use Threema web privacy.
Image from store
Description from store
Threema is the world’s best-selling secure messenger and keeps your data out of the hands of hackers, corporations, and governments. The service can be used completely anonymously. Threema is open source and offers every feature one would expect from a state-of-the-art instant messenger. The app also allows you to make end-to-end encrypted voice, video, and group calls. Using the desktop app and the web client, you can also use Threema from your browser.
This extension is designed specifically for the Threema web app. When activated, it overlays a dark screen with a grid pattern and a custom visual indicator, effectively obscuring the content to protect your privacy. The toggle is easily accessible via a popup menu, and your preference is saved automatically, ensuring that you can quickly enable or disable privacy mode whenever needed.