The Firefox Multi-Account Containers is a fantastic extension!
It allows me to have several tabs open without the cookies & trackers screwing up my ability to go from various email accounts and pages to others, without having to log out and log in multiple times.
I use it every day and absolutely love it!

Completely breaks syncing between Android and desktop.

Another FF product that deserves 5 stars.

Login using different accounts on the same site is great. Cookie peace of mind is great.

This is an awesome extension. A must have. An indispensable addition to your browsing experience and your privacy needs.

It only needs one thing: The ability to save container files. I want to be able to close a container, save its tab names and URLs in a file, and have the ability to get back to it when I need it again in its own window. That would allow me to just close a container I am not using at the moment and come back to it when I need it, saving maybe 90% of my memory.

Otherwise, impressive work. Thank you for your dedication!

This add-on is an absolute must-have! I honestly can't imagine using a browser that doesn't have this functionality. I'd be lost without it - no kidding! Thanks Devs for making this, it's a killer feature. I'm not sure how this isn't a standard feature in FF and all other browsers.

I was using multiple browser to separate work and home use, having dedicated accounts of the same site in different browsers. With this, I can have the convenience of cookies so websites remember their last state and the separation of task types I want. Plus, The colour-coding is a quick and subtle way to destiguish the different uses/accounts.