Free online tools for SEO

I found on the Internet several useful free online tools for Search Engine Optimizing and i like to share with you in my list here. please feel free to leave your comment under this post to help me improve my post :

www.backlinkwatch.com : Great site help you an free online backlink check, up to 1000 backlinks for free services, you can check more if you pay for their service. This provide you the Page Rank of the sites that links to your page, Outbound links, Anchor text of the backlink,...

savedhistory.net :  Bring you a power free online tool to digg into your site, your competitor site, with a lot of detail information.
Some awsome examples as
http://savedhistory.net/k/kindle-fire-text-to-speech


http://savedhistory.net/d/kindle-fireforum.com 

http://savedhistory.net/d/kindleworld.blogspot.com

push2check.com : This free online tool brings a lot of free tool for you to check all side of your site

Example as : push2check.com/kindleworld.blogspot.com

www.analyzebacklinks.com : Provide you a long list backlink to your site and a lot of interesting information related to your site

smallseotools.com/backlink-checker : Great site with a full online free tools


 www.opensiteexplorer.org   : Another online tool for check backlink ( a alternative for yahoo backlink checker )