From various geogebra creators:
Kaleidoscope 1
by Simona Riva
Drag the red dots and the center red dot to create a kaleidoscope effect.
Which figures have rotational symmetry?
By Alex Chik
Tesselate?
Kaleidoscope II
Be sure to turn trace on, and try out more or less lines. This applet ‘clears’ when you zoom in or out, so take a screen shot first if you love your design.