Is it possible to make a tree menu in K2 v2.6.1 from categories?

I found in K2 tools an option to make plain menu from categories, but I would like to:
1) make indents for subcategories
2) fold/unfold subcategories

Hi. You need to develop a module ( or search for an existing one ) for this.

Thank you.
I found the free module Extended Menu.
de.siteof.de/extended-menu.html
It fits my needs.

How did you do to use it with K2?