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 tablet, using Kindle for PC, 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.
Futa Choice: He transforms into a full-package futanari
The Laird's Little Sissy: Gay MM Taboo Historical Sissy Victorian Well-Hung Romance Erotica
FUTA: Futa Gift (A Science-Fiction Transgender Transformation Romance)
FUTA: Futa Gift 3 (A Science-Fiction Transgender Futanari Transformation Romance)
How to Train a Man in Seven Easy Lessons: An Erotic Femdom Novel
GIANTESS: Shrinking Compilation (GTS Shrinking Growth Macrophilia Romance)
Swapped And Fruitful: Taboo Fertile Gender Swap Erotica
Gender Shifter for Hire: The Mobster and the Mermaid
My First Futa Massage (Futanari Massage 1)
Disciplining the HuCow (HuCow Futa College 1)
HuCow MILF Menage (Futas & the HuCow MILFs 1)
My Park Ranger: Not Only Tents Need Pegging (Backdoor Pegging Romance)
Dominated By The Duchess: Victorian Taboo Historical Femdom Fetish Submissive Erotica
Susan's Shemale Surprise: On a weekend away Susan gets to play