A system for providing a predetermined set of functionality to primary applications is provided. The system includes a primary application interface that receives a user identifier, primary application configuration data and an application identifier associated with one of the primary applications from a plurality of primary applications, wherein the user identifier and the application identifier for each of the primary applications are different. A feature functionality system alters one or more features to match the primary application, the feature functionality system configured to provide a feature to a user associated with the user identifier and to transfer a primary application currency amount to the primary application or to award the user a prize upon completion of the feature by the user. A billing system interface unlocks external feature functionality for a certain number of interactions or a certain time period or generates the primary application currency amount.