Where do sharepoint hosted apps files live on 15 hive? I'm looking for the files that were downloaded to sharepoint when an app was installed. unlike features, I'm not seeing where the provisioned files exist.
They are not in the 15 hive. Any files needed by a SharePoint hosted app would be provisioned to that app's app web, which means they would ultimately be stored in a content database, not in the 15 hive.
Here also is a very helpful series of blog posts by Chris O'Brien on the subject of app architecture.