Not very amused with this addon.
Doesn't stay as an App Tab, doesn'nt save reading position and i have to reload the epub every time staring Firefox (Systemstart)

I can't go on the pages in the opened book.

Simply does not add a button to open already existing epub files. Something must be broken. Doesn't appear when I try to customize my buttons, either.

Can not open downloaded file

Il manque la possibilité de recherche de texte dans tout le document. Le CTRL+F de firefox ne fait que la recherche texte sur la page affichée. Cette fonctionnalité devrait être implémentée.

Seemed to work well at first. Some time later it stoped working and won't open any epub. Instead, it prompts to download the very same file I'm trying to open from myself, making multiple copies of it.

Extension don't work, every open epub open an infinity amount of popup new tabs

The privacy settings for this extension are appalling. Read all data and all websites? For an ePub reader? No thanks.