I've switched from Chrome to Firefox for privacy concerns recently, and disabled storing of all browsing data.
This extension allows accessing my accounts just as easy as before, but without carrying around my logins and cookies to every site I visit. Built-in password generator makes replacing my old passwords with 30+ symbols unique complex ones very convenient. That being said, it provides a significant quality of life improvement and is a must-have for internet security/privacy paranoiacs such as myself. Amazing extension indeed, wish I have found it earlier *thumbs up*