SEOquake is a popular and handy analytic seo-tool for Firefox, Chrome and Opera browsers. SEOquake helps to obtain an information about any site for a wide range of parameters such as page rank, Google index, Alexa and many others. Keyword Density tool serves to demonstrate a number of times a keyword or phrase appears on a web page. SEOquake has a parameter that highlights noffolow links.
SEOquake Toolbar shows values of the parameters under each search result in SERP of Google, Yahoo, Bing, Yandex, Baidu.
The SEOquake toolbar is easy to install and takes a couple of seconds.