HarperVoyager is supposedly giving away
15 free books. I've managed to get one so far and have had valid forms load for a few others. It seems to come and go. You might want to try your luck.
Here are the titles:
Dark Alchemy by Laura Bickle
The Oldest Trick by Auston Habershaw
The Veiled Empire by Nathan Garrison
Zeroes by Chuck Wendig
Shadow of Empire by Jay Allan
7 Sykos by Marshelia Rockwell and Jeffrey J. Mariotte
Black Dog by Caitlin Kittredge
A Crucible of Souls by Mitchell Hogan
Superheroes Anonymous by Lexie Dunne
The Book of Forbidden Wisdom by Gillian M. Kendall
The Tides of Maritinia by Warren Hammond
The Rogue Retrieval by Dan Koboldt
Earth Strike by Ian Douglas
Chosen Soldiers by R.H. Scott
The Cold Between by Elizabeth Bonesteel