If you in hurry and need a strong password for an account, PassPlex is an easy to use tool which creates strong password instantly. The best part of this tool is easy to use and options to create strong password. For example you can choose to have special character or numbers or both. You can also choose the length of the password and complexity level.
The only thing that makes me think twice is there is no mention of what kind of algorithm is used to generate the password and how the total thing works. The author should put up an about page and faq page to make the process transparent.
Passwords are the most confusing thing because you not need to remember them but also keep different for every account you have. It’s not necessary that a strong password is always strong because if its not used by many chances of guessing is relatively less. It is also possible to use simple password and then convert into a strong one using SuperGenPass which uses one way has algorithm.