Curatedseotools.com - Curated directory of the best SEO tools.
Seolyzer - Seolyzer is the ultimate SEO tool that provides you with all the information you need to improve your website’s health and performance.
SEO Marketing Hub - Learn SEO for free
SEOmator - SEO website analysis & audit tool
SEO Minion - Chrome extension & Firefox add-on to help you with SEO
Whatsmyserp - Powerful Rank & Serp Tracking. Completely Free.