Cube Kingdom is an application that can be used to create 3D models out of blocks with the same size and dimension. Squares can be placed, erased or coloured over with just a click or two, and there are sixteen different colours that you can choose from to apply to your building blocks.
Hold the middle mouse button to move your construction around the window. The scroll wheel can be used to zoom in or out, and models can be saved or retrieved by selecting the first menu bar option. You can also edit Cube Kingdom's text configuration file to change background colour and other settings.