This is a great extension. I am giving this review for library exporter, but really, it is a combination of the two extensions (library exporter and epub reader) since they work together.
I've been using epub reader for six years. It is by far my favorite extension and one of the only two reasons I love Firefox. Before this new update, the library was part of the extension, and it was the main attraction.
I could download epubs and read them directly in the browser, and the downloaded books were automatically saved in the epub reader library. Also, it was possible to drag and drop books directly in the firefox browser and be able to read them, and they were also added to the library. I have no idea why the publisher saw the need to separate the two. They gave a reason for storage space or whatever. I just think that, for people who like to read like me, we could be given a choice of where to save the files, and that would have been the end of that.
The other thing about the old version is that it was friendlier to people with bad eyesight, where bright lights are not very tolerable. I could change the color of the browser and read my books in full screen. But now with the new updates and separation of the ereader and library, this is only possible when reading through the library. If you read through the ebook reader, the full view does not grant full page of text, and the bottom bar is extended to an inch-thick white bar, which really hurt the eyes.
I know that you guys are great at what you do and we appreciate you taking the time to develop something this useful - and essential to some of us. It would be a shame if this extension goes out late this year as hinted. Please do what you do best and make it better if you have to, but don't leave out functionalities that made it awesome in the first place.
Thank you for all the years I've enjoyed this awesome extension.