Site Rank Data - View historical rank information of websites via time series charts.
SimilarWeb - SimilarWeb.com is a website analysis tool that gives you analytics information for any website.
HypeStat - HypeStat is free statistics and analytics service, where you can find information about every website.
Q-Stats - Get free marketing insights for every question on Quora.
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.
Seoxan - check seo report for any website, alexa ranking, server information, meta tags, authority, page speed and more