Stay Focused - More suitable with Google Chrome, this service enables you ensure you do not waste precious time on updating Facebook status or chatting with people.
SelfControl - V2 updates! - Custom time interval for distraction free mode - Ability to turn off ' always on' mode - Improved UI -- Self Control -- A simple app to keep you focused online by blocking sites that you spend way too much time on.
Freedom.to - Freedom is a productivity hack that lets you block apps, websites or the entire Internet on iPhones, iPads, Windows and Mac computers.
Cold Turkey - Cold Turkey is a free productivity program that you can use to temporarily block distractions so that you can get your work done!
Focus - New Tab page that gives you a moment of calm and inspires you to be more productive.
Baitblock - Adblock for distractions