It is very good package that I advice any one wants to check links, such as reciprocal links on remote websites to use it. However, in some sites it generates a notice error:
Notice: Undefined offset: 2 in /path/to**/crawler/Crawler.php on line 289.
when calling: http://saidbakr.blogspot.com
Also in some sites that have redirect it does not able to extract links.