SimpleCatalog

[Bigin]

Try the script here:

https://gist.github.com/bigin/0d4805b093...1223e37f5d

Put the code somewhere in your template and visit the page once. If it works then remove the code again.
The code alters your dummy category with an extra field named 'group' and updates all existing categories so that new field can be used to sort the categories by the contents of the field.

Then you have to modify your Extender plugin additionally. A new method 'renderFrontendCategoryList()' should be implemented. Also you have to extend the renderSection() method there as well. Your new Extender methods might look like this:

https://gist.github.com/bigin/a18dfa929a...2eae1beaee