eBully by Dave Conifer is currently free on www.Smashwords.com. This book is listed for young adults and teens. Conifer takes on the subject of cyber bullying in a fiction story. This is a topic all too many of our kids now have to deal with. I haven't read this book but it might be worth passing on to any middle school or high school students you know.
https://www.smashwords.com/books/view/5994