Sitebeam - Spelling mistakes, SEO, load speed, social media, code, W3C, accessibility & more in one tool.
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Ryte - Ryte is a web-based software invented for technical optimization for search engines and improvement of websites.
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
RankScience - Advanced Content Optimization Software for SEO
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.