One of these days, I want an ePub reader that I can fire up File Explorer*, double tap an ePub file, it opens and I can read it. I actively don't want a library, a bookshelf, or an ePub editor. I don't particularly care about support of other file formats, either. Both Freda and ADE seem to think they need to manage things for me. I don't.
Will Zulu just open a file and let me read it? And not do anything else? I've never tried it, since your original website makes my eyes bleed if I look at it too long.
*I actually use Resco, but it and the native app work the same way.