Curling up and reading a good book is a welcome de-stresser. Amazon is by far the industry leader in e-books, and the Kindle app is a must-have for Android tablet owners. Users will enjoy access to millions of e-books and a robust app interface that lets you customize your reading experience. With the Android app, you can bookmark pages, highlight passages, use the built-in dictionary and take notes in the margins. And your information is synced to the cloud with Amazon's Whispernet so you'll never lose your place, no matter what device you use. If you're an Amazon Prime member ($79 per year), you can access the Kindle Lending Library, which lets you freely borrow one of more than 350,000 e-books.