SonarQube - SonarQube, a core component of the Sonar solution, is an open source, self-managed tool that systematically helps developers and organizations deliver Clean Code.
Whatsmyserp - Powerful Rank & Serp Tracking. Completely Free.
Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
SEOmator - SEO website analysis & audit tool
CodeClimate - Code Climate provides automated code review for your apps, letting you fix quality and security issues before they hit production. We check every commit, branch and pull request for changes in quality and potential vulnerabilities.
Panguin Tool by Barracuda Digital - See your website's Google organic visit data overlaid with Google's major algorithm updates and changes to easily identify the impact on your website. Technology by Barracuda Digital.