Also consider expanding this idea, I added a new item to here http://buymeapie.userecho.com/topic/359769-category-names-and-groups-in-item-list-and-custom-categories/ it would go along perfectly with this feature.

Would be better IMO to add named category groups instead of having to move items around. That way it would cover this idea as well as many other. It would allow ability to make groups per this idea to go in order and add items to those directly as well as cover many other aspects that grouping can accomplish.