Every Friday I take the initiative to search through thew newly free titles on Amazon, and to identify those that might be of interest to trans* readers, fans, and lovers. Even if you don't have a Kindle, you can still download the titles through one of Amazon's free reading applications, and covert it (if need be) with Calibre. I can tell you I do most of my reading on my iPad, using Kindle for iPad, and it works beautifully.
Please do be sure to check the price before downloading anything, though, as most freebies are limited time offers, and some are specific to certain regions.
Magical Transformation Bundle (gender swap feminization erotic romance)
Hidden Desire: Erotic Transgender Fiction Box Set
Bitcoin Bimbo: Science-Fiction Transgender Erotica
Dickgirl Diaries 6: Rough, Wild and Out of Control - The Futa's First Time
BDSM Femdom Erotica: His First Surprise: Female Domination BDSM Erotica Bundle (Sissy Men Surprised by Dominant Women Book 1)
DRESS UP: THE FULL DRESS REHEARSAL (HUMILIATED HUSBAND Book 2)
Futa Shakes Her Pompoms (Futanari Cheerleaders 1)(Futa-on-female erotica)
Creamy Surprise (Futa Dariy Farm 1)(Futa-on-female, futa-on-futa, nursing, menage, creamy erotica) (Futa Dairy Farm)
Futa's First Day (The Futa Academy 1)(Futa-on-female, First Time, College erotica)
Eager for the Futa (Fertile Futa Meange 1)(Futa-on-Female, First Time, Fertile, Older Woman/Younger Woman Erotica) (Fertile Futa Menage)
Hook, Line, and Garter (Bitches and Queens Book 1)