Thanks for info Sri. (See Update below: It's now working !!!)
I installed the Add-On on Firefox 3.0.1
The install went fine - ie there were no issues of compatibility that surface.
Although I have Nightly Tester Tools already installed, it did not ask if I wanted to overwrite compatibility for External Application Button during the installation process.
In fact External Application Buttons Mod showed up as an installed Add-On and I could access the Option for the External Application Button Add-On when I went to the Firefox Add-On page.
My only problem is I don't see the "Applications" button when I right click on the Firefox Toolbar and click customize.
I can see the other Icons such as StumbleUpon, IETab, Scarpbook from my other add-ons that I can drag to the Toolbar.
But "Applications" button as showned circled in the attached picture is nowhere to be seen on Mine FireFox 3.0.1 Customize Toolbar screen compared to the attached picture below.
The picture is from :
http://www.inspiredg...rectly-from-firefox/The site says :
"After installation simply open the customize toolbar dialog and drag & drop the "Applications" button on the desired toolbar."
http://www.inspiredg...rectly-from-firefox/I wonder if perhaps there may be a conflict with another Add-on like maybe Custom Buttons 2 which I have also installed but not using.
Or maybe, I need to find a way to apply Nightly Tester Tools to it to "force compatibility"
Any suggestions. Thanks
Update:
After a couple of Firefox 3 restarts, "Application" appeared.
I don't know why it was missing previously.
Thanks once again.