Cloaking Checker
This tool checks to see if a certain domain or webpage is cloaking the Googlebot. According to Google cloaking is “a website that returns altered webpages to search engines crawling the site.” In other words, a human reading the site would see different content or information than the Googlebot or other search engine robot reading the site. Most of the time, cloaking is implemented in order to improve search engine ranking by misleading the search engine robot into thinking the content on the page is different than it really is.

This is a black-hat method of SEO and is discouraged.