One Hundred Free Books (ohfb.com)
Specifically, https://ohfb.com/category/romance/ is where you should go for the most free romances and similar items. Not all are free, but there are new entries every day that not even I can review them all. Needless to say, there are also plenty of OTHER genres for you to check out. Links to Amazon directly, just click on Amazon to download. You can also get a newsletter, but they don't segregate by genre. Browsing is better.
InstaFreebie.com
Enter your email (for mailing list) to claim a book, then follow instructions to get it into your reader. Process is not as smooth as OHFB, but you get books often not available anywhere else. You also sign up for the author's own announcement list. Be sure to sign up for the giveaways, which signs you up for a bit more mailing announcements.
You may want to use a separate email address to keep these from flooding your inbox. Signing up for a giveaway means signing up for newsletters from ALL of the authors that participated.
ExclusiveARC.com
You are requested to post a review when the book is actually released, so the author gets a bunch of honest reviews ASAP. This gets you books that are not even published yet... advance review copies.
Other newsletter announcing free books
You may want to use a separate email address to keep these from flooding your inbox.GenreCrave.com
LoveKissedBookBargains.com
BrazenBookShelf.com
eBookItch.com
RedFeatherRomance.com
RedRosesRomance.com
BookRebel.com
BookBub.com
