Good for me

If time usage blocking is added, would be perfect :)

So simple but so efficient

Simply and effective.

I Like it. I would find it better, if I could set a time to 'on' the blocker. Like, lets say, I want to go on twitter for 20 min and then want the Blocker to block me. So, I will set a time '20 min' before making the status 'on'.

Nice

自己正在写这样一款插件。好赞！

Great extension. However there are some annoying issues -
1. When you open firefox, it defaults to 'on', meaning if you are using your browser and don't need to block any sites (which is 80% of the time for myself) you will need to turn it off every time you open firefox.
2. This isn't as annoying but still weird - when you visit a site that is blocked, it redirects you to a mozilla addon link, e.g (moz-extension://0176857e-3c38-4d6b-bebc-2a1400810453/resources/redirect.html) rather than retaining the original link while displaying the impulse blocker alert.

Love the concept. Very simple and just what I was looking for. Only 4* as it doesn't seem to work with "https://web.whatsapp.com/". It's in the list of blocked domains but it still opens normally.

Occasionally gets stuck where neither "on" nor "off" are selected, but it behaves as if it is on. The extension needs to be disabled and re-enabled for it to work again.

Other than that, it works. Very simple.

Works great, but the stupid POS won't turn off.

Very productive. My only quibble would be that it should maintain the URL browsed to in the address bar or on the block page. I often open tabs of blocked sites for later reading only to see the impulse blocker page later on. Clicking on the Add-on button to toggle it on or off would be more convenient.
Anyhow, thanks for the great Add-on.