Showing a different navigation controller if it's the first time using the app

Showing a different navigation controller if it's the first time using the
app

The app is going to have a specific 'journey' for new users to follow when
they first use the application. This is a separate NavigationController
from the TabController which encompases the core app.
I know I can store whether or not someone has been through the process
before. My question is where would be the correct place to handle this
logic. Would you do it in the AppDelegate within
didFinishLaunchingWithOptions. Or within the TabViewController. Or
somewhere completely different?
I'm not too sure how I'd handle it within the delegate, it just feels like
a cleaner way to do it.
Within the TabViewController, I'd perform a segue to the
NavigationController. I don't want there to be any visible transition to
the NavigationController.