It's evidently not Moon+Reader,, sufficientlysecure.viewer, or Nook. This is what I want, one that can actually handle ALL files of a single type, all file types probably (though I prefer epub and pdf), show the covers properly (large enough and in full color, if applicable), not display files all the way over to the side and thus making them nearly unreadable, not getting stuck on a particular book and refusing to open any other, having easily adjustable brightness, allowing cover downloads if necessary, making it possible to group titles by subject or any other way, allowing title changes if it comes to that, and being available for free. I realize it's a lot to ask, but we're worth it.