In case you missed it...
If you're looking for a free open alternative to Amazon's Goodreads, there's a project just started called #Readlebee. You can follow them at:
You can help out with feature suggestions and code at:
https://gitlab.com/Alamantus/Readlebee
https://gitter.im/Readlebee
Readlebee uses a wikidata-based book database maintained by @inventaire which you can contribute to:
https://floss.social/@Readlebee/102793000211075677