Rated 3 out of 5 stars
Can't see the "Barcode" button. Firefox 6.0.2This review is for a previous version of the add-on (0.3.0.1-signed.1-signed).
I'm sorry, I'm trying to find a way to add the icon to the toolbar on installation, but haven't figured it out yet. To get it back you just need to click View > Toolbars > Customise, then drag the Barcode button to your preferred position on your toolbar