Sitebeam - Spelling mistakes, SEO, load speed, social media, code, W3C, accessibility & more in one tool.
WAO - WAO.io offers web analytics and optimization solutions.
Ryte - Ryte is a web-based software invented for technical optimization for search engines and improvement of websites.
Monsido - Monsido is an all-in-one platform that delivers the insights you need to build a better web experience for your visitors
RankScience - Advanced Content Optimization Software for SEO
Koalati - Automated website testing and quality control tools for developers and agencies.