The Spark controller is USB/MIDI interface and a MIDI controller, that acts like one when connected to any other MIDI receiving equipment, be it a computer, a synth, drumbox, iPad or any other MIDI instrument.
To toggle between its native Spark mode and its Generic MIDI controller mode (the one you can customize through the Control Center software), simply press simultaneously the three FX buttons, near the FX pad: Filter, Slicer and Roller.
The Spark controller doesn't generate sound by itself (It's just a controller!) and doesn't have user usable memory (just the flash one that holds its firmware).