Password Alert

Password alert is provided by Google for their Chrome browser is something that is very important, indeed a must have. I would always say do not use password managers in the past but the world has changed and browser based password managers are here to stay and will improve your security vastly. This browser add on will help protect your details while using their built in password manager and not only help secure Google sites but many others too.
Google is just one out of many of browsers which have a password manager and if you need cross browser support go visit 1password.com. Their service will reside as app based on your device. 

From Google:

Password Alert helps protect against phishing attacks.
If you enter your Google Account password or Google for Work password into anywhere other than Google’s sign-in page, you’ll receive an alert, so you can quickly change your password if needed.

Password Alert also checks each page you visit to see if it’s impersonating Google’s sign-in page, and alerts you if so.

Read more here: https://chrome.google.com/webstore/detail/password-alert/noondiphcddnnabmjcihcjfbhfklnnep