This extension is a life saver if you're an IT Admin that manages multiple accounts for your customers. Before I found this I wanted to kill myself managing Office 365 tenants. Now I can have dozens of tenants open at the same time without login issues.

The only reason I didn't rate this 5 stars is there is no way to easily sort the Containers list, really Alphabetical would be enough for me to rate 5 stars, but custom drag and drop ordering would be over the top. I have over a 100 containers, and often end up with duplicates as I miss them on first glance.