FocusBlocker is a light-weight add-on that blocks time-wasting websites to help you focus on real work. FocusBlocker can give you flexible control over when you want to block, which is superior than a schedule-based approach is you have a flexible working schedule.
Firefox version: https://addons.mozilla.org/en-US/firefox/addon/focusblocker-new/
How It Works
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1. Set a timer, say 10 min.
2. Browse freely for 10 min.
3. When time is up, the blacklisted sites will be blocked for 50 min (configurable).
Extore is a team of professionals who are passionate about creating extensions for web browsers. This devotion also gives us opportunity to appreciate work of other people. We get inspired by useful, open source extensions made by developers all over the world. Our strong belief is that one should share helpful add-ons with others. That’s why we’d like to present you our ever-growing list of favourite extensions that have inspired us. Moreover, as you probably have already learned, sometimes struggling for the best brings an end to the good. Talking about add-ons it often turns out that an upgrade is worse then previous version. Also it can become really tricky to get back to the beloved version of your favourite extension. That’s why we’re going to make not only the latest, but all versions of our favourite (and we hope yours too) add-ons available for download. No more compromises, just stick to the version you really like!