Just received this from Amazon:
A great new Kindle feature we think readers will love.
Page Flip is a re-imagined Kindle navigation experience that makes it easy to explore books while always saving your place. With Page Flip, readers can easily flip back and forth between pages to reference different parts of the book while they read.
Page Flip automatically saves the page you're reading in a book, pinning it to the side of your screen for easy navigation. Flip back and forth in a book with confidence, knowing you can instantly jump back to reading with a simple tap of your pinned page.
Zoom out to get a bird's-eye view of the book and quickly find what you're looking for. At a glance, easily recognize specific pages as you jump around. Pictures, charts, your highlights, and the layout of each page are easy to see with Page Flip's pixel-accurate thumbnails that automatically adjust as you change your font and margin settings.
Page Flip works with Kindle books that have Enhanced Typesetting enabled. Look just below the book summary on the detail page of every Kindle eBook to see if Page Flip is enabled for that title. The feature will be delivered as part of a free, over-the-air update starting June 28 to Kindle E-readers and the free Kindle app for iOS, Android, and Fire OS.
Click "Learn more" below for additional details and to see Page Flip in action.