I know Office 365 has more App Infrastructure in place.
I have been asked by user to get an app from the SharePoint Store. From what I’ve seen it requires setting up an App Server and an App Catalog. In addition to setting up some services like the “Subscription” service.
Is this correct?
Check out this step by step tutorial: http://www.scribd.com/doc/124831209/Configure-an-Environment-for-Apps-for-SharePoint-2013-Step-by-Step-Guide
You don’t need another server, simply enable some service apps and some DNS changes!