Blocks access to time-consuming websites (as you specify) to improve your productivity.
Block Site (formerly known as Stop Social Media) is a simple Chrome extension that improves your productivity by blocking the access to time-consuming websites (like during the working hours) as you specify in Options. Block Site is by default disabled and doesn't block any website until you say so in Options.
To open Options, right-click on the Block Site icon in the toolbar and choose Options from the menu.
Once you try to open a blocked site (e.g. facebook.com) in a new tab, that new tab will be instantly closed.
Let's be more productive!