FoxyPermissions gives you quick access to the about:permissions Firefox page from the toolbar. The add-on is basically the about:permissions page compressed into a small pop-up window that you can access and manage on the fly. If you’re visiting a website that you frequently use you might want to take a look at, and even revise, the permissions for it.
FoxyPermissions adds a button to the toolbar that you use to access the permissions panel. You can revoke access to location, camera, the accepting of cookies, and the microphone from the pop-up.
You can also purge all information stored by a website and all permissions granted to it by selecting it from the left column and clicking the ‘Forget about this Site’ button at the top right of the right panel.