The update, which brings the app to version 2.0, is largely focused on UI improvements. The look and feel of the entire Appstore experience has shifted as the white backdrops that used to be ubiquitous have been changed to shades of gray.
More settings have been added as well as you now have the ability to enable In-App Purchases, Parental Controls and get an easier view of your gift card balance.
If you don't yet have the appstore and would like to check it out, visit Amazon's Appstore page.
You can find more screenshots after the break.