This tutorial describes how to use the Whispersync feature.
INSTRUCTIONS & INFO
Whispersync allows you to synchronize your books, audiobooks, personal documents, games, and Amazon Instant Video across supported Kindle devices and apps. Note: Whispersync is on by default to ensure a seamless reading experience for a book read across multiple Kindles.
From the home screen, swipe left on the Menu bar.
Tap the URL field.
Enter "Amazon.com" then tap Go.
Tap Your Account.
Confirm your account password, then tap Sign in using our secure server, if prompted.
Tap Manage Content and Devices.
Scroll to, then tap the Whispersync Device Synchronization field.