I'm aware this is an old post, but I've recently been trying to read books in PDf format, and I have to say that KOReader could do better. Admittedly, and to quote the author of k2pdfopt, "PDF is just about the worst source format there is for displaying on e-readers", but KOReader's implementation of it in continous view mode of reflowed PDFs duplicates the last line on a screen as the next screen's first line. This seriously interrupts reading and cognition. The author of k2pdfopt also recommends the
Book Reader Android app. I tried it, and it neatly separates pages in reflowed PDfs, without repeating lines. It's an
open source project, so maybe the devs could take a look?