The program is shareware. The unregistered version is limited to a 2D display in Google Earth. The full version allows 2D and 3D display in Google Earth as well as SVG and PNG images.
It also includes a database with thousands of cities for when you are offline.
The program can be downloaded here .
The direction of the sun can be displayed as 2D projection or as 3D vectors. The 3D option allows to see obstacles such as tall buildings already in advance.