Subitem allows the user to create additional items, as "child" of the item that is clicked on. Insert subitem creates the association, the parents of the items. Users can filter on created items.
Free forever. No credit card
Easy to use
You just need to go to the Grid View, select the item you want to insert and click on the subitem - alternatively, you select the item and press the shift + enter combination.
Many Options - Many Filters
You can choose filter for subitem: delete, copy, increte, decrete...