Block Site (formerly known as Stop Social Media) is a simple Chrome/Firefox extension that improves your productivity by blocking access to distracting websites as you specify.
Click on the icon. Enter sites you would like to block, prepend ! to exclude site from blocking, example:
facebook.com
instagram.com
youtube.com
!music.youtube.com
reddit.com
!reddit.com/r/MachineLearning
Choose how to resolve blocked site: Close Tab, or Show Blocked info page.
Blocked info page shows what url was blocked, based on which rule it was blocked, and optionally a blocked count over a chosen period of time: All Time, This Month, This Week, or Today.
Block Site doesn't collect any personal information or data. Any user settings are stored in your browser only.