If you can't get enough of George R. R. Martin's epic Game of Thrones fantasy saga, there's a new way to get detailed information on its world and characters on your phone and tablet. Random House has introduced A World of Ice and Fire, an interactive guide to the series, for free on the App Store. The app features more than 500 character profiles, details on nearly 400 locations and interactive maps, accompanied by officially sanctioned artwork.

One of the most novel features of the app is the ability to prevent spoilers by selecting the latest book you've read in the series. By doing so, you remove any references to characters and locations you haven't encountered yet from entries.

Initially, the app contains eight character profiles and two maps, but can be expanded by purchasing packs for each of the novels priced at US$1.99 for A Game of Thrones and 99 cents for the subsequent four books. An in-app purchase of all five book packs is available for $4.99.