I haven't used Wattpad, but since you mentioned transgender characters in novels, I just wanted to point out a few recent ones (which I only learnt about relatively recently myself). There's still very little visibility for transgender issues or characters in fiction, broadly, as the field of trans* literature disproportionately has favoured nonfiction narratives thus far, but here are some I've read that you might consider checking out, if you haven't already:
Kim Fu - For Today I Am a Boy
Ariel Schrag - Adam
Rachel Gold - Just Girls
Alex Myers - Revolutionary (sort of--more about transcending gender boundaries, but the author is FTM)
Shani Mootoo - Moving Forward Sideways Like a Crab
And for a short story collection, I would highly recommend Casey Plett's A Safe Girl to Love.
Still a long way to go, but trans* fiction is a slowly emerging category.