I've written an extremely basic sample module in the Hello World vein for aspiring module authors to examine and dissect. Download the tarball from the link below, and copy it to your WebTool modules directory. Extract it by typing tar xvfz webtool-module-sample-<version>.tar.gz and then access it by entering https://yourhost:1023/modules/sample/ in your browser's address bar after logging in to the WebTool.
This basic sample module can be useful in understanding the necessary pieces of a WebTool module and how they interrelate in a simplified way. It can be used as a convenient starting point when writing your own modules as well.