Thanks to all for the various recommendations.
I need to take a closer look at (especially) FB Reader and Kybooks (again), I guess, since they got such strong recommendations on the foregoing pages. I can only say that when I tested them a few years ago, they didn't strike me as serious competitors of my (largely dysfunctional) Marvin & Moon+ Reader combo.
In any case, the only reason I visited this noxious thread again after a couple of years (happy with my opening post from 5 years ago; it quickly went downhill from there, but that's par for the course on MobileRead) is that I've recently become aware of the
BookFusion app that does have
potential to become a worthy replacement for us Marvin (ex-)lovers one day, just like Marvin replaced Stanza for us.
It's not there yet by any means, but I've just composed my opening report on BookFusion (frequently comparing it to what Marvin offers and doesn't offer) here:
https://www.mobileread.com/forums/sh...d.php?t=348805
If you have any feedback on BookFusion, I will appreciate your posting it there (I'll be expounding my initial report on BookFusion later on) – or if you have even better replacement suggestions for Marvin.
I suppose, though, that neither FB Reader nor Kybooks offer the
3-way cross-platform functionality that BookFusion does, right? iOS + Android + web (Windows for me). If not, that would be a definite point in favor of BookFusion. (Of course, Kindle and Play Books are lost causes.)