The HTTP Scoop sniffer by Tuffcode is a Mac OS web sniffer doing multiple HTTP watches. This tools stands in a row of other HTTP protocol sniffing tools.
The application lists the HTTP requests and responses on Mac:
Features
The sniffer features the ability to catch most of the HTTP parameters such as headers, cookie, cache, response content. Both request and response data are available as text or as the hex dump, responses being savable to a disk. The timeline is not present here.
Loaded images are also viewable from within the application. TCP/IP packets are available for viewing too.
If you are running a web server or an application server on your machine, then their requests will be cached as well.
The usable interface adds more to the sniffer; it allows the viewing of POST data along with client request parameters.
HTTPS/SSL capture trick
Since HTTP Scoop catches the data in the IP layer, it’s not able to decrypt encrypted traffic. One way to get around this is to use a “reverse proxy”, which allows requests to the proxy over an unencrypted connection (which HTTP Scoop can intercept) and forwards them on to the destination server using HTTPS. Each user utilizes this trick at his own risk, however. For more instructions on how to do it on Mac read here.
Summary
HTTP Scoop is a good tool for any web developer or web administrator and for any one interested in HTTP/HTTPS analyzing.