Классный виджет.
Пользуюсь давно.
Косяков нЕ обнаружено за всё время))

This is Firefox's killer app

nice

really useful for web developement, much more convenient than starting multiple browsers in order to use to test a website with multiple accounts at the same time, also now you can sync containers between devices, making it easier to recreate your configuration on a new machine

Really useful, it improves your productivity avoiding to open different browsers or profiles.