WebCleanser by Elias Owen

This add-on provides a safe, minimal toolbox to highlight elements on the active tab and store a default CSS selector. It demonstrates secure Firefox WebExtension practices — no inline scripts, no remote code, strict content security, and minimal permissions. The popup lets users send a highlight command to the active page; the options page stores a default selector. Content scripts are injected on demand using the activeTab permission to minimize access. No site data is sent anywhere.