Remember referring tour URL on install
When a user installs the iOS app from the page for a specific tour, the installation process doesn't end with that tour being loaded. They are instead required to scan or search for the tour again. If at all possible, a tour ID should be included as a URL parameter for the link, and the installer passing this ID on for action.
Otherwise, users without the app installed who scan the QR code have to do so once before installing, and again after installing.