Here are some awesome Islamic (or Islamically appropriate) books on Wattpad that you might love :
The Best Of Us and The Both Of Us by Hopemore
Letters To An ATHEIST by DuniyaKiEkMusafir
A Non-Hijabi's Perspective by betterleftunsaid_x
Her Shield by pearls4falasteen
Converting The Bad Boy by Aishabella13
Zia by sara_is_hungry
Our Three Winners #DeahYusorRazan by HopesPrayersNSmiles
Muslimah Posts by ElEleganteFriki
Growing Up Arab by ArabiaFelix
A Step Closer To Jannah by I_Luv_Allah_Forever
The Whole Page of gazawritesback
The Girl in the Green Scarf by PearlandIvory_
That's it for now, but this list will keep growing Insha'Allah.