FocusDragon by FocusDragon

FocusDragon is a website blocker built for serious deep work on macOS. The Firefox extension is the in-browser half of that — install the FocusDragon Mac app from focusdragon.app, set up a block, and Firefox redirects any matching tab to a calm blocked page for the duration of your session.

What it does:
• Blocks websites, URL substrings, search terms, and regex patterns, all defined in the Mac app
• Redirects matching tabs to a clean "Blocked" page instead of just hiding content
• Works alongside Safari and Chrome — same block list applies everywhere
• Locked enforcement: blocks survive Firefox restart, extension disable attempts, even uninstalling the Mac app mid-session

Requires the FocusDragon Mac app (free download at focusdragon.app). Without it, the extension does nothing — there's no standalone mode.

Privacy: This Firefox extension transmits no data to any remote server. It communicates only with a local native-messaging host installed on your Mac by the FocusDragon app. (The FocusDragon Mac app itself uses anonymous product analytics and crash reporting for its own diagnostics — but that's the desktop app, not this extension.)