I have created a simple Provider Hosted App ( straight out of the Visual Studio 2013 box )
The App has been granted "Read List Permissions" in the app manifest.
When the app is deployed SharePoint Online asks the User to select the list that the app can access. This should give it permission to read one specific list on the Host Web.
I cannot figure out how the MVC Provider Hosted Web part of the application actually determines which SharePoint list the end user has granted it permission to read.
Presumable it gets some sort of token to tell it which list it can read? Or is their a CSOM/JSOM call that will reveal which list it can access?