1. A computing device comprising: a processor; and one or more computer-readable storage media having computer-executable instructions stored thereon that, when executed, provide a service platform comprising: a global integration layer configured to enable an application to allow a user to access and use services of which the application is not aware from within the application; a common control integration layer that provides a control that can be hosted by an application, the control configured to be populated with services of which the application is aware and the services of which the application is not aware; and a custom integration layer that provides a set of Application Programming Interfaces (APIs) that can be used by the application to customize a user interface that includes at least one service of which the application is aware and at least one service of which the application is not aware.