Whatsmyserp - Powerful Rank & Serp Tracking. Completely Free.
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
SEOmator - SEO website analysis & audit tool
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
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.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.