A take on the classic horizontal oscilloscope + ‘trails’ ideas. Get the cool effect by turning ‘Persist’ on.

Knob1 = Oscilloscope Shape & Size Selector. 3 divisions: lines, circles, lines+circles.
Knob2 = Size of ‘Trails’
Knob3 = ‘Trails’ Opacity
Knob4 = Foreground Color – 8 positions
Knob5 = Background Color