Good question. I only noticed that if I go to the bookmark list, and tap/hold on one of them, it brings up a small dialog where I can enter more text in its nam

Good question. I only noticed that if I go to the bookmark list, and tap/hold on one of them, it brings up a small dialog where I can enter more text in its name. I don't know of a way to make it obvious while reading that there is a bookmark at that point, but I'm no expert, and haven't really explored the other e-book readers. The f-droid.org app (and probably web site) refer to https://librera.mobi https://librera.mobi which might have more info in the FAQ, and there is apparently a link to the author's email (at least in f-droid) who might accept $ for support or added features for all I know (or similar for other app authors) :) After this thread dies, you're welcome to contact me if there is something else I can attempt answering, via my profile url.