Whatsmyserp - Powerful Rank & Serp Tracking. Completely Free.
HttpMaster - HttpMaster is a professional software tool for testing and debugging HTTP applications, primarily aimed at REST API applications and web services.
SEOmator - SEO website analysis & audit tool
Hoppscotch - Open source API development ecosystem
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.
Request inspector - Debug web hooks, http clients