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.
Gender Swap Top: Transgender Erotica
Lollipop Switch: Gender Swap Fiction Bundle
Dickgirl Diaries 4: Stretched and Ridden with Thirteen Inches - The Futa's Taboo Lust (Futa on Female) (Transgender Forbidden Affair) (Innocence First Time) (Interracial Romance Erotica)
Dave's Not Here, Ma'am: Spanked by the Futa Boss
The Queen's Twelve Dancing Sons: An XXX Fairy Tale with an Erotic Twist
Futa Force: Futa Files 001
Midnight Ride (Futa Cowgirls 1)(futa-on-female, voyeuristic erotica)
From Doctor to Cleaning Lady: Femdom tale of a top doctor's forced feminization and humiliation as an MILF
Teasing the Futa (The Futa's Seed 1)(Futa-on-Female, Taboo, Risky Erotica)
Seducing the Faithful (The Futa Church 1)(Futa-on-female, futa-on-futa, menage, sinning erotica)
Erotic Bundle #9 Tressa Barber 3 Pack
A Natural Mistake
Transgender Adventures: Turnabout
Alan Lennox and the Temp Job of Doom (The Future Next Door Book 1)