Just a little heads up that the website collecting free Kindle horror, fantasy, sci-fi, apocalyptic, and paranormal ebooks has updated as of March 9th, 2018. [link]
Most of the books are only temporarily free as part of a promotion, so check them out while you can!
(And if you read any of them, try to remember to give the author a review!)
Edit: It looks like some of the books on there have already had their free promos expire, but they’re still worth taking a look since most are in the range of $1-3.