I am a long-term user of "Password Hasher" which is no longer maintained. This add-on seems to be a good replacement... IF this one issue is solved:
It is dangerous to enter the master password directly into the web page. A variant where it is entered in a pop-up dialog is desperately needed. Why not put it in the bubble or in the dialog which opens when clicking on the hash in the toolbar?
For new users: This is not such a big problem for you as long as you do not use the compatibility mode.
I'm aware of this problem, but am currently lacking time to implement such a large change. See https://github.com/simu/passwordhasherplus/issues/3 for an ongoing(ish) discussion on the topic of hiding the master password from the web page.
