When reading through the documentation of the diverse google maps offerings in the APP store, you will find some paragraphs about google API keys. Using the 3.1 version, and the latest version of the widget, I can not find an API key property. Everything works. Am I correct you don't need an API key to display the geographical data on the maps for commercial use?
Read the license for the details of the use of Google Maps. This says that the application must be free and freely accessible. If your app is commercial check this carefully.