If I put videos in a folder (any folder at all) on the SD card, the video player app finds and plays them, but this doesn't work with Kindle books. If I create a folder called "Books" on the SD card, copy a Kindle book there, then locate it within the "Files" app and try to open it, I get a message "Open File - no application can perform this action".
So I'm a little bit stuck now. Is there any way to open Kindle books that are stored on the SD card? I suppose I could keep them on the SD card, then copy them to internal memory to read them, but that seems a little clumsy.