WhisperSync for Voice is a program that was designed to build synergy between eBooks sold by Amazon and the audio edition from Audible. It was designed to give readers a discount for purchasing both the eBook and audiobook edition and flip between the two wherever you left off. For example, if you are reading a novel at night and stop reading at page 92, you can pick up on the audiobook where you left off when commuting to work the next day. This used to just a program exclusively for the Kindle Fire line of tablets and now is available on the official Kindle app for iOS and Android.
Professional narration is available for more than 45,000 Kindle books and growing—including popular best-sellers from an array of genres. You can easily add professional narration to your favorite Kindle books with one click using Matchmaker (www.amazon.com/matchmaker), a service that scans your Kindle library to find which of your Kindle books have a companion Audible version available. Audio upgrades are available for as little as $0.99, with upgrades to bestsellers like the Outlander series and The Hunger Games series available for as little as $3.99.
Whispersync actually gives you discounts on the audiobook edition if you already have the Kindle book. This allows for a few dollars in savings if you want to take advantage of Whispersync for Voice, but sadly there is no bundling program yet to buy both at a lower price.
The new Kindle app is available via iOS and the Good e-Reader App Store.