Rated 2 out of 5 stars

For advanced users. Requires knowledge of JavaScript. Spent 2 hours on the support site. When the forum for adding a button to launch an external app. was found the moderator wasn't sure if it worked. I would suggest a list of working scripts on the home page of the site that could be easily downloaded and implemented. Uninstalled Custom Buttons.

Installed External Application Buttons 0.7.3.4 (google it). EAB works with FF3/XP.

This review is for a previous version of the add-on (2.0.7.6). 

You shouldn't need the scripts even as a novice. Simply go to the forum, click on a button and it will install in your browser.

Don't see the button you want then please request it and folks usually try to grant requests.