Block Site
Block Site (formerly known as Stop Social Media) is a simple Chrome extension that improves your productivity by blocking access to distracting websites as you specify.
Usage
To configure, click on the B icon in the toolbar and select Options from the menu. Enter sites in the textbox, leaving a new line for each site, like this:
facebook.com
youtube.com
youtube.com/* (this will block subpaths, for example: youtube.com/watch?v=b9zS4gskVeM)
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