I have to say -- the iPad is a terrific platform for interactive ebooks, but so far, I haven't been very impressed by the options out there. I do use my iPad for reading a lot, but the vast majority of my reading is done in either iBooks or a comic book reader. It's very rare that I will pick up an app that's designed to work as just one single book, no matter how many extras or interactive features are included.
However, I'm happy to say that Steve Jackson's Sorcery! is a clear exception to the general rule. It's excellent, and mostly because the book it is based on (actually a "gamebook" released back in the '80s) was already interactive to begin with. Add in iOS interactive touchscreen, some excellent graphical flairs and a whole lot of polish, and what you end up with is something very akin to playing a Dungeons and Dragons game, where the few game elements present are really just intended to ignite your imagination, and get you role-playing in the game's world.
Sorcery's story is pretty basic: You're a hero who sets out into a dangerous world, hoping to either save or conquer it. And the combat gameplay is extremely simple as well -- you essentially guess whether your opponent is attacking or defending, and trying to mirror their actions to do damage as you can. But the real meat of Sorcery! is in the inbetween. You travel from town to town, talking to various NPCs and even solving a few puzzles, all while exploring this world through the game's scrolling text.
I really have no problems at all with this app -- I was fascinated by the story's well-written text, and while the gameplay isn't extremely innovative, it's paced well enough to keep the action rolling. The one hitch might be that you need to use your imagination on this one, so if you're expecting a game like Skyrim, that will draw out the world for you, you might find this a bit boring. But as a die-hard pen and paper RPG player and a fan of Steve Jackson's work, I think this is an excellent adaptation that's well worth a purchase. You can pick it up from the App Store for $4.99 right now.