I wrote this ABAP report (taken from SAP sample of tree class usage) because I was bored to try to remember the name of that program to solve that problem…
Using this report I have a central point to collect all of them (reports, functions and classes).

It's a tree based on a simple table that contains folder and item (the report, function or class) definitions and relationship.

Below a screenshot:

Functions available:

• double clicking an item runs the report
• clicking on icon opens the maintenance for the table containing the tree structure
• clicking on icon refresh the tree (needed if you add or change an item)
• clicking on icon opens the ABAP editor for the selected item