Shows you the keyword densities of Top 5 keywords of your page.
Keyword Density Tool calculates the keyword densities of top 5 keywords of a page. While calculating the keyword density, common helping words like "is, was, in, of, etc." are ignored. So, this will give you a better idea about the keywords in your page and will help you in formulating your keyword strategy.
The extensions will not work on pages in https://chrome.google.com because of an inbuilt security feature in chrome.