WhatSize is described as 'simple tool that allows the user to quickly measure the size in bytes of a given folder and all subfolders and files within it' and is an app in the OS & Utilities category. There are more than 50 alternatives to WhatSize for a variety of platforms, including Windows, Mac, Linux, BSD and Android. The best alternative is WinDirStat, which is both free and Open Source. Other great apps like WhatSize are WizTree (Free Personal), TreeSize (Paid), Baobab Disk Usage Analyzer (Free, Open Source) and DiskUsage (Free, Open Source).
- Take back your hard disk space with Spacie. Spacie scans files and folders on your hard disk and display them in column view, with size information shown up-front. View 24 alternatives to Spacie
The app seems to be no longer updated. Last Mac version, 1.2.5, released in March 2012, can be still bought from the Apple AppStore. Windows version is no longer available.
- Paid • Proprietary