Analyze Your Web Page To See If It's 'Search-Engine-Friendly' For Specific Phrases

Simply adding a keyword to a page isn't enough to improve your rankings in search engines. It is also dependent on the placement of the keyword or phrase, and whether you have it in the page's title or not. With this Web Page Analyzer, you can discover whether your page is search friendly or not, then take the necessary steps to make sure it is.

http://www.webmaster-toolkit.com/web-page-analyser.shtml

Analyze Your Content to Identify Missing Relevant Keywords

If you're looking for a way to increase relevancy for your website and in turn increase page rank, then try using the LDA Content Optimizer tool. This tool will crawl your site and crawl similar sites which rank higher. This tool will provide you with keywords missing from your website that are being used by your competition.
http://www.virante.org/seo-tools/lda-content-optimizer

Check the Response Codes of Your Header and Act Accordingly

When a visitor loads your website, all sorts of various responses can load for them. To help diagnose HTTP Header problems, use this HTTP Header Response Tool & Code Key. You can discover what code loads for your website, then see what steps you need to take to fix it.

http://www.internetmarketingninjas.com/header-checker/

Flag Your No-Follow Outgoing Links

No-Follow links can be a powerful tool for your website, but they can be a harmful detriment if not handled properly. Use this No-Follow Finder to help discover the amount of no-follow links you have at a certain URL, then flag them to make sure you're taking the proper steps moving forward.
http://seotoolsforyou.com/tools/no-follow-finder/

Validate Your Website's Mobile Readiness

If you haven't given any thought to the mobile readiness of your website, you're missing out on a lot of revenue potential. People aren't just visiting pages on their phones, they're purchasing and more. With the W3C MobileOK Checker, you can find out if your website is ready for mobile phone users.

http://validator.w3.org/mobile/

Check your SEO

Great Tool to check your SEO: http://tutor.rs/

Site's SEO with this Free Microsoft Toolkit

 No, the toolkit doesn't just provide metrics and tips for increasing your site's influence in Bing. This Microsoft SEO Toolkit will help you increase website traffic and revenue, by increasing your influence with major search engines. There are tools to help you improve customer experience as well.

http://www.microsoft.com/web/seo/