Developed by Bryan D. K. Jones, Muzzle is an app designed to silence notifications that you receive whenever you are screen sharing. It can be downloaded from the developer's website and installed with ease by even the most novice user.
It doesn't have a proper user interface, but more of a main menu, located in the mac's main bar. Therefore, it has no themes, or advanced graphical customizations. However, it's highly responsive to user commands and consumes a low amount of system memory - because it sits 100% on idle and does no polling.
As per what it can do, it's simple: Muzzle silences user notifications, so you don't be disturbed while using the screen sharing function.
More, the app restores the state of your system to what it previusly was before starting the screen sharing.
Also, if you set up Do Not Disturb at specific times, Muzzle will not interfere with that schedule.
All in all, Muzzle is a simple but useful Mac utility. It doesn't use third-party code, so it has no unexpected vulnerabilities. It would be nice to have a real interface and maybe some themes to choose from, to make it cool.