Thanks, Serena. I’m glad you’re enjoying it!
I don’t currently have plans to link the posts that appear on indiebookclub to a third-party service like Amazon or GoodReads. However, since the ISBN is sent in the micropub request to your site, plugin/theme developers could use that information to link the posts on their site to a third-party service.
I have made some improvements during the IndieWeb Summit which I will write more about soon. It’s now easier to make bookmarklets to pre-populate the new post form. This should allow developers to create few-click options for adding books without typing anything. It also makes it easier if you see someone else’s read post and want to quickly add it to your list.