FocusBlock от thora

FocusBlock is a powerful productivity extension that helps you stay focused by blocking distracting websites during work sessions. With three preset focus modes (Work, Study, Deep Focus) and a built-in Pomodoro timer, FocusBlock makes it easy to eliminate distractions and maintain concentration. Each focus mode comes with pre-configured blocked sites, or you can customize your own list. The extension uses Firefox's webRequest API to intercept and block access to distracting sites, redirecting you to a friendly reminder page instead. The Pomodoro timer helps you work in focused 25-minute sessions, automatically activating site blocking when started.