Relief! I love saving all windows and closing one will lose the saving. To get this to work with the new UI, which omits the File/etc drop down menus, I first installed, then I clicked Toolbox (bars) icon / Customize / Dragged Exit button to appear in my list of items. To the android person, this is the desktop plugin, for Android close all, see QuitNow, https://addons.mozilla.org/en-US/android/addon/quitnow/?src=hp-dl-featured
It quits firefox. It's now slightly less useful with australis UI, as there is now an exit button on the menu dropdown (easy to get to and close to the X anyways) however I still use the addon. This lets me kill ALL firefox windows currently open, of which I normally have three. This lets all three come back with restore when I open it back up.
After placing it near the regular X on windows, it lets me kill 'em all with ease, which is exactly what I wanted from it.
Can you make it compatible with Thunderbird and SeaMonkey. I like the concept as explained by gadgetman, before that I was skeptical about this add-on and wondering that can there be review for such nifty or useless add-on so I took closer look and saw all 15 reviews and realized the usefulness. Once again please make it compatible to Thunderbird and SeaMonkey.
I've always used this extension in the past. But recently, it was made incompatible by the latter versions of Firefox. There's a simple fix for this. Simply open the extension (very easy using mc with Linux, with no need to even extract the files), and edit the install.rdf file. Change the version to 3.0.*. This can likely be done in the future as well with forthcoming updates of Firefox as well.
Placed the red button just below the "X" on the upper right and it works like a charm. Tested with 3 windows open, one with about 8 tabs, and FF was completely shut down in seconds. Then re-opened and all was preserved. Also installed it into Thunderbird where it works just as well.
The same as going to File/Exit, only much easier and the button is located where I am accustomed to going for most all programs. And it's small at only 8kb, and don't believe it adds any delay to the startup time, although I neglected to check that before and after install.
Thank you for a job very well done (Why didn't the Mozilla writers think of this a long time ago?) Hopefully they will incorporate your great little feature in version 3! Miles