Problems with Apps from App Store

I have configured the App Store setup using Nauman Ahmed's very helpful blog on App Store (I think successfully anyway).

I think its configured properly because all of the steps in his guide have gotten me to the point where SP says that the Bamboo World Clock app and the Habanero app for messages are installed.

When I go to use the apps in a page (though), the div shows a 404 error and nothing is shown.  If I go and look at the IIS logs, I see a 401 error - not authorized. 

I am a site collection admin and in a group with full control permissions.  The app provisions properly so this just doesn't make sense.

Is there some other permissioning process for the app store apps that I am missing?

http://www.naumanahmed.com/2012/07/sharepoint-2013-app-management-service.html#!/2012/07/sharepoint-2013-app-management-service.html