1. An Integrated Development Environment (IDE), executing computer instructions in a computer-readable storage medium of a computer system, suitable for use in developing a Virtual User Interface (VUI) application, the IDE running on the computer system and comprising: a development window for graphically constructing a visual layout of a User Inteface (UI) to correspond to a virtual layout of a Virtual User Interface (VUI) generated by an ultrasonic sensing unit externally coupled to the computer system and with its own targeted processor and memory for receiving executable program code compiled from the IDE specific to instructions of the targeted processor; and at least one descriptor that identifies a response of a user interface component in the UI to touchless sensory events applied to a corresponding virtual component in the VUI generated by the ultrasonic sensing unit, a compiler for compiling a source code of the VUI application into at least one code object using imported target processor and memory configurations from the ultrasonic sensing unit; a linker for converting said code object into relocatable code based on the targeted processor and memory of the ultrasonic sensing unit; a code builder for building said relocatable code into an executable code object; and a flashing module for managing a down loading of the executable program code object over a connection into a flash memory of the externally coupled ultrasonic sensing unit associated with the target processor and memory, where the computer system is communicatively coupled to the ultrasonic sensing unit by a wired or wireless connection for developing the VUI on the computer and down loading the executable code object into the ultrasonic sensing unit.