This FireFox extension simplies having multiple accounts in your AWS org.
To get started, install the extension and browse to your startpage:
https://org.awsapps.com/start#/
It will expand all your accounts and profiles, which will be stored in the extension.
Create a new Multi-Account Firefox container with the same name as either your account name or account number.
When browsing to your startpage, it will automatically sign in the matching account, set the name of the acount in the navigation bar, and change the color to the selected color of your container.