Obblog 2 (copy/paste the code to the obblog2 textarea) Users:

Lights bucle: (Kimmo Lindholm)
Lights bucle
Counter and Hex Digit:
counterdigit

Binary 4 bits signed adder with overflow and hexadecimal digit:
binary4bits_8-7.png

Binary Tree: (6 bits)
binarytree.png