Nick D’Aloisio taught himself how to write software when he was 12. At the age of 15, he built a free iPhone app called Summly. This app automatically summarizes news stories, which is great for small screens. Later, when he was 17, he sold his app to Yahoo! Inc. for nearly $20 million. After the deal took place, the app was eventually taken down, but it had already been downloaded almost 1 million times.