The nice part too is that at the end of the day you own and host your own data. In a similar vein, one might also look at Calibre [https://calibre-ebook.com/], which is free software that is somewhat like iTunes for books/e-books. It's highly configurable and in addition to also archiving and storing actual ebook versions of your books (and magazines, newspapers, or other digital files), it allows for additional common metadata or even custom fields. It also has a variety of plugins including one for GoodReads which allows you to sync your book data from GoodReads to your own computer/server.