I regularly create lists of newly free kindle books extracted from various Amazon categories. One of those I created today was for Kindle books related to low carb or ketogenic diets (mostly cookbooks):
Clicking on the “CA” or “DE” or “UK” link in the top right hand corner of the document will change all of the book links from USA to Canada or Germany or the UK. But they may not be free there as they are in the USA. Usually, but not always.
For easy navigation through the books, clicking on the blurb of any given book will bring up the next book in the list, to make it easy to go through them sequentially. Each section header has an index of the various categories available, which also shows the number of books available in each category. Clicking on the section header itself will bring up the full Amazon search listing of free books for that category.
I started making these lists for my own use when an Amazon policy change in 2013 basically gutted all of the web sites listing free Kindle books.