Only play/pause works. Personally for me it is not enough, but if you do not need anything else - I recommend it.

All the buttons I'm using control only play/pause, despite the add-on recognizing the different keystrokes

They mentioned a Firefox bug causing only Play/Pause buttons to work, but they only work when the browser's in focus. Useless when you want to pause a song or video while in another window or a game.

Works fine, but the browser window still needs to be selected for it to work.

In Spanish keyboard, it only obeys to the dieresis key. Despite having specified a custom shortcut.

I read the description, and I understand that it's not the plugin's fault, but it really does suck how Firefox decided to complicate things like this. Now you can only play/pause, no next/previous track! 5 stars and a donation if this gets fixed. So sick of going back to the music tab.