For a better maintained version of this project have a look at: https://github.com/WhiredPlanck/diskusage

DiskUsage app for Android

DiskUsage provides a way to find files and directories on storage card which consumes a lot of space.
It displays diagram on which directories are displayed proportional to their size, also a few levels of subdirectories are displayed. Users are allowed to zoom in to look at specific directory content.
Purpose of the program is to provide a way to find and cleanup spacehogs on storage card. It is not general purpose file manager.

Screenshot for an ancient version:

YouTube video: https://www.youtube.com/watch?v=TIiCQfWdtVg