Passliss is an Open Source app that allows you to generate passwords in an efficient manner.
This password generation app is easy to use, allowing you to create unique passwords, and it will also verify the strength of the new password. The only thing that we would like better is the ability to key your own password, as this would allow you to test the strength of some of your existing passwords, but it certainly is not a deal killer.
Passliss permits you to configure the length of the password and whether or not it will have uppercase, lowercase, special characters, and numbers. It includes mild appearance customization.