Here's how you can download the free Kindle app for Macs.
1. Go to the Kindle app preview page.
2. Click the View in Mac App Store button.
3. Click the Free button to download the app.
Here's a description and screenshot of Kindle for Mac:
"The Kindle app gives users the ability to read Kindle books on a beautiful, easy-to-use interface. You’ll have access to over 1,000,000* books in the Kindle Store, including best sellers and new releases. Amazon Whispersync automatically syncs your last page read, bookmarks, notes, and highlights across devices (including Kindle), so you can pick up where you left off on another device.
Get the best reading experience available on your Mac:
• Shop the Kindle Store for over 1,000,000* Kindle books, including New Releases and 107 of 111 New York Times Best Sellers. Over 610,000* of these books are $9.99 or less, including 79 New York Times Best Sellers.
• Start reading immediately with three free books: Pride and Prejudice, Treasure Island, and Aesop’s Fables. Thousands more free classics are available in the Kindle Store.
• Get free book samples – read the first chapter free before you decide to buy.
• Customize your reading experience by choosing the background color and font size.
• Instant dictionary word lookup with 250,000 entries and definitions. Select a word to view the definition. Use the Google and Wikipedia links to get more information.
• Search inside the book to find a character, topic, or section you want to revisit.
• Simply click on either side of the screen or press the arrow keys to turn pages.
• You can also read your Kindle books on your Kindle, Kindle 3G, Kindle DX, iPhone, iPad, PC, Android-based device, BlackBerry, and Windows Phone 7-based device. Our Whispersync technology syncs your last page read, notes, bookmarks, and highlights across devices, so you can pick up where you left off. "