Calling other iOS applications directly from a custom Notes application helps to create a seamless and enduser friendly user experience on the iPad. Currently @URLOpen is limited to generating http(s) and mailto links. It should be more flexible and allow to generate any type of link.
Example: I would like to generate a tel: link and be able to initiate a phone call. Other examples would be to generate a SMS, start a Facetime conversation, directly open a ressource in the IBM Connections mobile app, etc.