Newt Group LLC

An app to help get an idea of the relative sizes of files and folders on your disk. Choose a folder, and it instantly starts showing results of the largest files in a pie chart, without having to wait for the entire scan to finish.

It uses read-only access to perform analysis, so there's no concern about deleting the wrong files by mistake. If you see a large file that you want to clean up, you can delete it via Finder or Terminal.

Highly responsive and can scan multiple other folders as well.