The authentic source code for OpenBullet 1.4.4 is hosted on under the openbullet organization. Be wary of fake download sites offering "pre-hacked" versions or cryptocurrency miners.
OpenBullet is a web testing suite that allows users to perform requests to a target web server. Originally inspired by other testing tools like Sentry MBA, OpenBullet was designed to be a more modern, customizable, and user-friendly environment for creating "configs."
https://github.com/openbullet/OpenBullet/releases/tag/v1.4.4