ViewDNS.info - Free DNS related tools including Reverse IP Lookup, DNS Propagation Checker, Chinese Firewall Test...
Site Rank Data - View historical rank information of websites via time series charts.
Whats My DNS - Instantly check your domain names current IP address and DNS record information against multiple name servers located in different parts of the world.
Q-Stats - Get free marketing insights for every question on Quora.
NsLookup.io - A simple and powerful tool for querying DNS records
Seoxan - check seo report for any website, alexa ranking, server information, meta tags, authority, page speed and more