Focus Mode από Levent B.

Focus Mode is a Chrome extension built for Manifest V3 that helps you reclaim
your attention. Add the websites that distract you — social media, news, forums —
and start a timed focus session. While the timer is running, those sites are
blocked via Chrome's built-in declarativeNetRequest API, so the blocking is
efficient and doesn't require any read access to page content.

When you try to visit a blocked site, you are shown a beautiful, motivational
blocked page with a countdown timer, a rotating inspirational quote, and
encouragement to stay on task.