WheresTheFreeSpace is a system utility that displays the size of files and folders so that you know which folders are taking the most hard drive space. This way, you can take measures to recover some of that space when you are running a little low. This utility was designed for PowerPC processors, so Macs running OS X Lion or Mountain Lion will not be able to run this app.
You can scan entire volumes or specific folders. In the main window, you will see a drop-down menu with all the volumes mounted on your Mac. When you select one, you will see a list of all the folders and files that make up your volume. The interface looks a lot like the older versions of Finder. Even the old-school icons are used. Next to each file or folder name, you will find its size in megabytes or gigabytes, its relative size and the number of sub-folders in each folder. In between brackets, the app displays the percentage of space that each folder takes up.
In short, WheresTheFreeSpace does work well and it could be useful for anyone who needs to pin-point the folders that hold the most files. However, given its price, and the fact that it looks old and it is very limited, this app is not one I can really recommend. I have seen far better solutions with nice graphs and better interfaces for considerably less money.