OpenScreenShot for Firefox does not collect or transmit screenshots, captured page content, browsing history, or usage telemetry.

Screenshots, capture history and preferences are stored locally in your browser. Image editing and export take place on your device. Files are saved or images copied to the clipboard only when you request those actions.

No account is required. Support and donation links open external websites only when clicked; those websites have their own privacy practices.

Source code and support:
https://github.com/PGHQdev/OpenScreenShot