Availability of In-App Service
Each operating system (Android, iOS, Windows) offers a service that sets up the device for in-app purchases at the corresponding app store. The MobileTogether function mt-in-app-purchase-service-started() checks whether the service has been started on the respective operating system. It returns true() or false().
In the example project, this functionality has been enabled as a button-click action on the button Is InApp Service Available? (see screenshot below).
When the button is clicked, the function mt-in-app-purchase-service-started() is called and the ServiceAvailable node in the $PERSISTENT tree is updated based on the value returned by the function. Since this node is the page source link of the label on the right-hand side of the button, the node's value is immediately displayed in the label.