An electronic device coupleable to a display screen includes a camera system that acquires optical data of a user comfortably gesturing in a user-customizable interaction zone having a z0 plane, while controlling operation of the device. Subtle gestures include hand movements commenced in a dynamically resizable and relocatable interaction zone. Preferably (x,y,z) locations in the interaction zone are mapped to two-dimensional display screen locations. Detected user hand movements can signal the device that an interaction is occurring in gesture mode. Device response includes presenting GUI on the display screen, creating user feedback including haptic feedback. User three-dimensional interaction can manipulate displayed virtual objects, including releasing such objects. User hand gesture trajectory clues enable the device to anticipate probable user intent and to appropriately update display screen renderings.