The Crooked Boy
This book can be downloaded and read in iBooks on your Mac or iOS device.
A group of apparently close-knit friends venture to an abandoned hospital for a scare, but when things go wrong - terribly wrong - as soon as the night begins, the kids receive more than what they asked for, and when one of the teenagers is murdered, they put into motion a domino effect of supernatural horror, led by an evil older than humankind itself...a sleeping evil that was put to sleep for a reason. Its name: the Lord of the Flies.
Honestly, I'm gonna give my honest opinion because I'm about to be honest. Honestly this book got me shook. I almost cr*apped my pants. But this book is so creative it will forever remain one of my top horror books.