This is a great app for studying chess games, strategies, tactics, openings, and endgames! Half of your screen displays the book and the other half displays an interactive chess board. The chess boards follows the books text automatically or you can control the pieces yourself. This app will surely become the "app of choice" for those who are serious about chess. As a fairly new app, there are less than a dozen chess ebooks available but more are sure to follow.
Chess ebook user about ePlusChess Books