The way that settings are handled has changed in R2.0. Settings is now not anymore a separate application, but it is a special folder with short-cuts to settings applications. The old settings are still implemented in the settings-app, but with a new argument for the application, one of the old settings windows can be selected.
The special folder for settings is located in /usr/share/ctb/settings on the device. See \iRex\ctb\data\settings in the sources to see how the settings are now implemented with the .desktop files.
When adding new settings a separate application can be written, a shortcut to the application needs to be added to /usr/share/ctb/settings so that they become avaialble when the user selects settings. An example of a settings application can be found in: \iRex\hello-world\settings.