I'm developing a SharePoint add-in with provider hosted app. One requirement is to uniquely identify add-in instances. The user can install add-in multiple times. Provider hosted app stores mapping between add-in instance and user's selection. This enables us to customize the appearance of our app content.
I've tried SPAppToken. It is the same across all instances. SenderId parameters are different each time add-in instance is loaded.
I'm looking for a unique identifier for each add-in instance. Does this exist?