Seolyzer - Seolyzer is the ultimate SEO tool that provides you with all the information you need to improve your website’s health and performance.
Check My Links - Highlights broken links on page
Panguin Tool by Barracuda Digital - See your website's Google organic visit data overlaid with Google's major algorithm updates and changes to easily identify the impact on your website. Technology by Barracuda Digital.
SEOmator - SEO website analysis & audit tool
Internet Marketing Ninjas - Internet Marketing Ninjas provides an SEO tool that offers extensive information related to your site’s health and well-being.
SEO Minion - Chrome extension & Firefox add-on to help you with SEO