Host AdBlocker - Block By Domain, is an addon that let you easily block unwanted domains (based on hostname matching). Badge icon shows the number of blocked items for each website.
It has 19 predefined filter lists to choose from (see options page). Each list has several rules in it, once you select multiple lists the addon will merge them to construct a single list with unique rules.
Once you add this addon to your browser, a button will appear in the toolbar. This button shows that the addon is active (with a Red color). Pressing on the button will disable the addon (Grey color). Now, before using the addon, please visit the options page and choose desired filter list(s). By default, three lists are selected. Please note that, you can choose to print blocked URLs to the browser console. To do so, please mark the first setting in the options page.
In order to support websites that rely on advertising, Host AdBlocker let you whitelist desired domain(s). Some domains are added to the list by default (including addon's homepage), but you can edit this list at any time. In order to add a domain to the whitelist, please open addon options page and add desired items to the designated area (comma separated).