Isn't it easier to just use Charles Proxy (<a href="http://www.charlesproxy.com/" rel="nofollow">http://www.charlesproxy.com/</a>) or mitmproxy (<a href="http://mitmproxy.org/" rel="nofollow">http://mitmproxy.org/</a>) for those stunts? I can see the value for anyone not familiar with those tools, but for me as a developer, this is clearly something that can be solved without depending on a third party server.