There was an app released a little while ago that turned out to be Verizon specific and not available for AT&T networks.
I’ll play about a little and see if I find if this one is Android/AT&T friendly.
EDIT: IT IS now full AT&T/Android compliant and downloaded, installed, and ran properly.
As suggested, go to the Android Marketplace on your phone and search for “Disney Mobile Magic” and you will be directed to the proper place. So long as the “Download and Install” button is available, you’ll be fine.