I didn't even have a Firefox account and made one just to write this review. The developer is SUPER RESPONSIVE. Anytime I've had an issue they are very prompt with a reply. That is very rare with any app. With anything really. Tells you alot about them and the pride they take in their product. Onto the app. It works seamlessly with Youtube and it is the best one out there. Period. There's been a few hiccups here and there but as I mentioned, their support takes care of it.