Charles

Summary
Charles, or Charles Web Debugging Proxy, a cross-platform HTTP debugging proxy server application written in Java. It enables users to view HTTP, HTTPS, HTTP/2 and enabled TCP port traffic accessed from, to, or via the local computer. This includes requests and responses including HTTP headers and metadata, such as cookies, caching, and encoding information with functionality targeted at assisting developers analyze connections and messaging. Charles is actually available for download in the App Store for $8.99, but is available to Apple employees free-of-charge via Apple's Self Service MDM. Aside from being free for Apple employees, it does not appear that Apple has made any sort of changes to the app whatsoever.