I've only used this extension for 5 minutes and I already love it! Surprisingly, it still works, despite that the last update was 4 years ago. I installed it only because of this option: "Allows for the forced discarding of specified hostnames". And it works better than expected! It doesn't allow opening tabs leading to a specific site. Not just "open and then autoclose the tab", as I thought it would. It plain and simple doesn't allow the tab to be created! <3
