It looks like a paid for database ($39.99 for the book database) -
https://www.readerware.com/index.php - and it looks like it's not specifically just for digital files. It seems to be a version of something like LibraryThing or GoodReads as it tracks paper books as well as electronic books.
Given the price, it's not something I'd bother with - I have Calibre to manage my ebooks and LibraryThing to manage all my reading material both physical and digital.