Font maker: lets user interactively design a font. You specify font size (width and height in pixels), a magnified grid is displayed, arrow keys to move around it, turning the "pixels" on/off, tell what "character" it is, repeat for as many characters as you want, look at the entire font, use the font to compose text, save the font, load a font file and modify it...
Arabesque: create geometric patterns à la arab. Specify number of rows and columns, radius and eccentricity of ellipses, to use colors or just white, to fill the circles or not.
Rosettes: regular polygons that can rotate, dilate/shrink, move and collide