WebSec Coach by Xenolith AB

WebSec Coach is a firefox extension with the purpose of helping users with web security by informing them of threats and ways to avoid them. The extension contains multiple guides for different kinds of threats and other security related subjects.

Password helper:
The addon contains a built in password helper that will appear when the user is entering passwords. It gives tips about password strength and offers an option to test the passwords.
There is also a password guide for learning more about passwords and how to remember them.

Domain blocker:
WebSec Coach will block domains that are considered harmful/untrustworthy for the user. It also provides an option to learn more about different kinds of threats through an interactive guide.

It also has the ability to warn about external links, clicked outside the browser (opt-in in options).

Phishing reminder:
The extension can show a reminder about phishing when visiting a webmail inbox (currently only Simply, Gmail and Outlook). This feature can be enabled in options.