SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
SEOmator - SEO website analysis & audit tool
SEOquake - SEOquake provides a browser extension to conduct on-page SEO audit.
AccuRanker - AccuRanker is a cloud-based rank tracking tool.
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.