If you need complete seo tools for checking SEO Stats or Website Rank you can go here http://www.seocondition.com/
There are some grea free online tools that can check the on page SEO of your site and some premium tools that can check the on page and off page SEO of your site and your competitors, but if you ensure that you have the keyword in the title, description, meta keywords, and spread naturally in the content, you will cover the on page SEO aspect
Hello friend, Here is different types of seo tools you can use it. http://www.seocompany.ca/tool/seo-tools.html
I think most useful and working free tool is your brain and you have to use that. Proper use of this tool will give you the success.
http://www.seoserp.com/web_tools/google_top_1000_serps_checker.asp is a good one for checking the rank of your site for a keyword up to 100 pages deep.