Former Wall Street Journal technology reporter Yukari Iwatani Kane delves deep inside Apple in the two years since Steve Jobs's death, revealing the tensions and challenges CEO Tim Cook and his team face as they try to sustain Jobs's vision and keep the company moving forward.

Steve Jobs's death raised one of the most pressing questions in the tech and business worlds: Could Apple stay great without its iconic leader? Many inside the company were eager to prove that Apple could be just as innovative as it had been under Jobs. Others were painfully aware of the immense...