Rated 4 out of 5 stars

This is a really good extension, and probably the only one which works flawlessly with Google Play Music. It contains all the major lyrics sources and currently it finds anything I listen to, even some obscure artists missing in the other extensions I've tried before.

I would only add an optional feature to view the lyrics in a separate window. I understand one of the most loved functionalities of this extension is the ability to read the lyrics in the same window where the media is playing the music/video, but the case of sites such as Google Play, Spotify or Pandora is that they are all about the music, I don't really need to go back to the page once it started a playlist or an album, besides there is not enough room in some of these web pages to view all the content plus the lyrics, even with a decent resolution configuration. I think it would be more practical to have a small window next to my other programs so I can glance at the lyrics anytime.

Thanks for your work.

This review is for a previous version of the add-on (3.12). 

Thanks for the review. This feature is on my wish list as well, but I currently have no plans/time to add new features to the addon.

EDIT: Version 3.14 introduced support for lyrics in a separate window.