Review for Live HTTP Headers by Bob Bane
Rated 5 out of 5 stars
Great Add-On - I haven't found anything similar in another browser. I think such a functionality should be implemented in the browser itself. It provides the most useful information when you need to check on a server app communication. Without this I won't be able to troubleshoot anything.
This review is for a previous version of the add-on (0.16).To create your own collections, you must have a Mozilla Add-ons account.