To help combat Fraud, Google Licensing has been implemented into the latest Android version of the app (4.0.1).
This license check requires an internet connection and only needs to be performed once. After Google has verified the app license a special key is stored on your device and internet connection is no longer required after the key has been stored.
For more information about this and a quick overview from Google, please click HERE
If you get an “Unlicensed” screen, please wait 5 minutes to let Googles licensing system catch up and try again. If that does not work, uninstall the app and reinstall it.