Amazon is finally bringing Kindle's X-ray feature to Android devices, three years after it launched and two years after it became available on iPhones and iPads. X-ray, for those who haven't had the chance to use it yet, provides some sort of an encyclopedia-and-dictionary-in-one for each book you read. It displays a list of characters and the parts of the book they appear in, particular terms and their meaning, as well as significant phrases appearing throughout the text. It works for both novels and texbooks, so long as you click the X-ray button somewhere on the app's top bar. Considering the update introduces other useful features, including push notifications and the ability to make flashcard sets, the app has now become a better tool for both schoolwork and leisure reading.