It depends on which book.
If you're looking at Eat Right 4 Your Type then the app is more accurate. It's the most up-to-date food list available and reflects more recent research.
If you're following one of the "Health Series" books (for Diabetes, Arthritis, or another health condition) or Eat Right 4 Your Baby (and are currently pregnant and/or nursing) then follow the book, not the app. These books have a few foods with different food values on purpose, specifically tailored to specific health issues. The app, while up-to-date, isn't as specific as those books.
If you're looking at Change Your Genetic Destiny, aka "The Genotype Diet" and abbreviated GTD, then you only follow the book, as it's a different system than BTD (blood type diet) with different nutrients and toxins emphasized.