Apple just updated the official Apple Store app that allows iOS device users to make and track purchases, check in for reservations, and schedule Genius Bar and One-to-One appointments. The first new feature included in version 2.2 of the app is the new Express Checkout that was previously only available to online shoppers through Apple’s browser-based online store. The feature enables quicker purchases by allowing you to skip the shopping cart checkout process and simply enter your Apple ID to have purchases billed directly to the credit card on your account. The Express Checkout also allows you to specify whether to ship or pickup purchases by default or to “Ask me every time.”

Another new feature exclusive to iPhone 4S users is the ability to let “specialists know when you’re approaching the Apple Store” to have your products ready for pickup.