Charles is a powerful HTTP proxy/HTTP monitor/Reverse Proxy tool that enables a developer to view all of the HTTP traffic between a computer and the Internet.
Charles allows developers to view requests, responses and HTTP headers which contain crucial cookie and caching information. It's very useful for enabling debugging the content of HTTPS sessions. It works by simulating modem speeds by effectively throttling bandwidth and introducing latency so that developers can experience an entire website as a modem user would.
Charles is a useful tool for any developer that needs to view HTTP proxies on their Mac.