Google Wallet has been updated, adding single sign-in support, and the ability to add credit and debit cards more easily. Single sign-in, present in other Google iOS apps, lets you sign in to Google Wallet if you have already signed in to other Google apps on iOS. When the list of accounts is presented, simply select the one you wish to use and you're done.
You can add credit or debit cards to Wallet using your phone's camera. To do this, go to the app's settings by tapping the gear icon in the sidebar, then tap "Credit and debit cards". Hit the red '+' button at the top and when presented with the new card screen, tap the camera in the Card number box. Google Wallet will capture both the card number and the expiration date automatically.
This update also connects you with the new Google Wallet card, a card that allows you to spend your Wallet balance anywhere that you can use a MasterCard. If you've verified your identiy with Wallet, then you can order your Wallet card right from the app. Just go to My Wallet, then tap "Get your card" when it's presented to you. Google will ship the card off to the address you've provided. The Wallet app will update you on when your card is used, and what your remaining balance is when you use it.
This update can be downloaded from the App Store now.