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
instagram.com
youtube.com
!music.youtube.com
twitter.com
reddit.com
!reddit.com/r/MachineLearning

Sites starting with ! will be exception to the rule, allowed.

Choose what should be done when you try to visit a blocked site, options are:

1. Close Tab
2. Show Blocked info page (page that shows an information about the blocked site)

Last but not least, see a checkbox to enable/disable the blocking.