Try my Sciter Notes ( https://notes.sciter.com https://notes.sciter.com ). It uses database for storing stuff but you can map books to folders on hard drive. A

Try my Sciter Notes ( https://notes.sciter.com https://notes.sciter.com ). It uses database for storing stuff but you can map books to folders on hard drive. And those folders can be under control of DropBox, GoogleDrive etc. So you can read shared stuff on any device using browser there.