Favicon needs to be transparent and multi-resolution

The favicon.ico should provide bigger resolutions, to be used where icon sizes are bigger.

http://egressive.com/tutorial/creating-a-multi-resolution-favicon-including-transparency-with-the-gimp

In Chrome, go to Tools > Create application shortcuts..., check Desktop, click Create.

SchoolTool will open in a new window, without location bar or tabs. Nice.

But the icon on Desktop is supersized ugly :(