From December 19th, 2014 to November 29th, 2018, 50% user give 5-star rating, 50% user give 2-star rating. for SoftBlock chrome extension.
very simple, works fine for me. excellent in giving me a reminder to do usefull stuff instead of going to other sites
I wish it worked, because it is so simple and would suffice, but its broken in Chrome Version 39.0.2171.95 The block works, but the button to go to the website (after selecting a period of time) doesn't work, so you can't get to the website at all.