SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
SEOmator - SEO website analysis & audit tool
MarketMuse - MarketMuse is an artificial intelligence platform for Semantic Content Optimization.
Lumar - (Previously DeepCrawl) Hosted SEO spider to analyze and find problems with websites.
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.
SEOquake - SEOquake provides a browser extension to conduct on-page SEO audit.