I don't think you're the target audience - it's a tool oriented at people implementing activitypub servers, and provides a set of tools for debugging and testin

I don't think you're the target audience - it's a tool oriented at people implementing activitypub servers, and provides a set of tools for debugging and testing that an implementation meets the activitypub spec. As someone working on an activitypub implementation, even without any prior knowledge about the tool, from the screenshots and feature list I was immediately able to work out what it was for. Things like verifying message certificates and activitypub compliance were things that I was doing manually in an ad-hoc way before, but this tool seems to provide a standard way of testing it.