If you are using Firefox for your APEX development you may want to check out my list of add-ons I’m currently using for the web development. If you have any useful add-ons you are using, drop me a note!
Download it at https://addons.mozilla.org/firefox/1843/
Live HTTP Headers
With this addon you see what’s going on in the background, what data is transfered from and what is coming back from the server.
Download it at https://addons.mozilla.org/firefox/3829/
It adds a tab to the Page Info dialog box, which shows the cookies of the current web-page.
Download it at https://addons.mozilla.org/firefox/315/
Just downloaded and installed this add-on. Very feature rich, lot of options, …
Will see how useful it is during development.
Download it at https://addons.mozilla.org/firefox/60/