If you're an email host, an actor would be an email account. If you're dropbox/evernote/wunderlist, an actor would be a user account. If you're a payment proc

If you're an email host, an actor would be an email account. If you're dropbox/evernote/wunderlist, an actor would be a user account. If you're a payment processor, every payment would be an actor. If you're a messaging app, an actor would again be a user. If you have user groups, then every group would also be an actor. For your use case. An actor would be configuration for an app. If you have multiple apps (or services), they would have their own actors.