1. A mobile device comprising a user interface, a communicator, a central processing unit (CPU), and a storage unit storing instructions executable by the CPU, the instructions configured to implement: a first application module configured to receive a first input command from a user through the user interface; a second application module configured to receive a second input command from the user through the user interface; and an assistant interface configured to translate the first input command into a first semantic atom and to transmit the first semantic atom via the communicator to an external server to perform functions at a first external service; the assistant interface further configured to translate the second input command into a second semantic atom and to transmit the second semantic atom via the communicator to the external server to perform functions at a second external service; the storage unit further storing libraries mapping received input commands to semantic atoms, each semantic atom encapsulating digital data specifying a function to be performed, the first and second semantic atoms corresponding to semantic atoms stored by the storage unit.