There is no better way to read e-books than on the stunningly simple Kindle app. The storefront is easy to navigate, and the selection of titles runs deeper than the plot of a Haruki Murakami novel, chockablock with both full-length tomes and Kindle Singles (the perfect commuter fare — not so short that you don’t care, not so long that it outlasts your ride).

Responding to the modern reader’s desire to consume on multiple platforms, the app automatically syncs your progress through a story across devices. Start a book o...