Block URLs you don't want to open.
For example, you can't stop to open some webs like "facebook.com", "twitter.com" while you are working. You want to concentrate on work, but those webs are really so interesting. "URL Block" is a really good choice for you.
I have the same trouble, so I create this extension. Hope it is good for you too.
Plz let me know if you have some trouble or advice.
My email: firstname.lastname@example.org