Rated 4 out of 5 stars

Great tool and allows complex PW's for banking and investment sites. I would only ask serious encryption is added to the database containing the PW's in the event the computer is compromised or hacker gains access to files. Darren-Chaker

This review is for a previous version of the add-on (2.8.1-signed). 

using Firefox Password Store

QuickPasswords uses Firefox's built in password store (and has all the advantages of that including Sync), encyrption used is Triple-DES. You can add better security by using Firefox options > security > change master password and choosing a secure one here, and never install addons / plugins from sources you do not know and trust. Ideally you should only install Addons from addons.mozilla.org to be safe.