[Ken Maltby]

Actually, Sergey's Coolreader port will use whatever file structure that is available to it, including one made for Koreader. I recently updated to a more current pbchess package, and notice a number of improvements. One of the neat things is that you can set "Startup" to "Recent books list", which gives you something like Koreader's "History". Once you have selected a book from your "Koreader library" the "Open File" option should open in your Koreader directory structure and the big up arrow should get you to the start of it. Then you can browse just like you can in Koreader.

There is a new "File Manager" added to the launcher tools and games, this is just that and not the file selection process for Coolreader. It is much more useful for actual file management than the limited features in Koreader's "File Manager", especially as it is not restricted to files that are ebooks/documents that the reader can use. It would be of no use for browsing to select a book to read.

You should have what you are looking for already, once you get comfortable with navigating Coolreader's Open File controls. The port of Coolreader is not the same as the Android port, especially as to how it accesses files.

Luck;
Ken