I use Librera on my eInk Boyue LikeBook Plus. I'm very pleased with it. I use it mainly for epub books.
What I like most is that the app almost completely "disappears" from the display and just let you focus on reading the book.
Three suggestions:
I sometimes seem to double tap and advance two pages. And have to go back. Breaks the focus. Perhaps some form of delay/debounce between the first few taps in a sequence of taps?
I would like to be able to disable pinch to zoom and drag. Sometimes I move or zoom the display unintentionally. Breaks the focus to fix it.
Support for automatically grouping/browsing books based on calibre hierarchical genres/tags would have been great! As far as I know there is no eReader app that does that directly. And calibre is very popular on this forum.
https://manual.calibre-ebook.com/sub_groups.html