Wrote this plugin while experimenting with custom post types for recipes. The recipe plugin market seem saturated and the big players in that niche have very loyal fans. So I re-purposed by recipe plugin for book reviews so that I could experiment with WordPress and its plugin API.
Submitted it, forgot about it until I got an email from a user. Checked the plugin's support page and saw that I had 4 missed support requests as WP.org does not auto-subscribe plugin authors to new threads on their plugin support page. So, I brushed off some of the code-cruft and implemented some new features at the request of new users.
I am now at a watch-and-see period with Gutenberg and I am researching ways of growing my user base.
Plugin link: https://wordpress.org/plugins/recencio-book-reviews/