The Initial Purchase includes the full set of functionalities. No additional functionality will come with the In-App Purchases. The In-App Purchases are only to allow the management of more devices at the same time. 5 Devices are allowed with the initial version of the App. You can choose to add 5 more devices or an unlimited amount. These In-App Purchases have a 1 year expiration date so they will need to be renewed once a year.