Functionaly the app is the same as v1.2, which we've reviewed previously here on AAWP:
Reading is comfortable as well. The albeit limited palette of colours (black on white, black on sepia, or white on black) keeps the feel of a book. Font size can also be selected and you can turn the brightness down in the Kindle app, which is handy at night time.
Once you're into your book, all the UI furniture gets out the way and lets you get on with the simple process of reading, You can swipe the pages left and right, although just a tap on the left or right hand side of the screen is enough to turn a page. Tap in the middle and a progress bar slides in, with the thin menu bar appearing at the bottom of the screen for the aforementioned settings.
Unfortunately Amazon haven't done anything else with the application. The lack of fast-app switching is almost unforgivable on the new platform, personal documents are still not supported, and even though media can now be stored on a microSD card on some handsets, I can't load my own eBooks over a USB cable and have the Kindle app read these files - only those purchased or downloaded via the Amazon Kindle store are available.
But it's Kindle, and I have bought in to that platform, so I'm actaully very happy the app has been updated and someone is watching over it, even if they don't appear to have a lot of resources to improve the code. There's nothing new in the package for Windows Phone 7.x users, so the update will not be available in the Windows Store... but v1.2 is still available and gets the job done. To be honest, they're not going to be missing anything.
(Hat tip to WP Central, who confirmed the installation bug).