This is really a good book if you're an aspiring app developer for the modern smartphone or tablet computing revolution, but as much as I'd love to give this a 5 i have to be honest and give it a 3.
i'm a huge fan of the windows platform (let the apple hating and anti-android people commence their attack), but this book is aimed more at those two platforms than the windows RT/Mobile system, a lot of the principles can be adapted and with a little work will produce good results. If you're looking to make apps or games to sell on your chosen platform then please buy his other book "Level Up", it's one thing to make a game... but it's another to make one that people want to buy.
Overall I will really give this a proper go and make something, but do I feel inspired enough to break out the keyboard and start coding. No, not today... but maybe if i need something to do one day