Ranked in these QuestionsQuestion Ranking
Pro Free & Open Source
It is absolutely free and released under the GPL.
Pro Allows ordering disk by size
This way you can find what is taking most of the space.
Pro Offers choice between analyzing whole disk or just a specific folder
Con Doesn't seem to work on Mojave
On launch you get an Apple error that says it is not supported by this OS version and once it is done analyzing the drive it crashes.
Con Crashes on Sierra
Crashes on Sierra when resizing windows.