HypeStat - HypeStat is free statistics and analytics service, where you can find information about every website.
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.
Q-Stats - Get free marketing insights for every question on Quora.
Quantcast - Quantcast Corporation is a digital marketing company that provides free audience demographics measurement and delivers real-time advertising.
Seoxan - check seo report for any website, alexa ranking, server information, meta tags, authority, page speed and more