The Kindle’s X-Ray feature is an excellent differentiator from other eReader apps. It’s like a specialized Wikipedia for each Kindle book, curating details about characters, locations, history, and many other facets of both fiction and non-fiction texts.
The X-Ray feature is finally available in the Kindle Android app as part of the version 4.8 update. When you’re reading a book just tap the middle of the screen, then touch the X-Ray icon on the top menu bar (if it’s not there, then your particular book isn’t supported).
You’ll then be able to browse or search through the X-Ray content; it auto-hides spoiler information by default to avoid ruining the story for you. The X-Ray feature also hunts down people, terms, images, and collects together any notable pieces from the text. It also suggests similar search terms; just touch them to find out what Kindle has cooked up for you.
Along with X-Ray, the Kindle app now offers push notifications for book downloads and promotions (you can turn these off in the settings). There’s also an option to create flash cards from textbooks - though it is limited to very specific tomes right now.
You can now better control the audiobook playback within books, too. Many eBooks have an audio component that can be purchased together with the book or added on later through the Kindle app.
Why this matters: While Amazon makes its own Kindle eReader and Kindle Fire tablet hardware, a ton of people read their Kindle books on Android tablets (or even phones, if you have a big-screened device like the Nexus 6 or Galaxy Note 4). So keeping feature parity among platforms is important to prevent you from being tempted by rival platforms like the Nook or Google Play Books.