WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Scanner - This tool uses a sunburst chart to display the usage of your hard disk or other media.
TreeSize - TreeSize tells you where precious disk space has gone to.
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.
Rymotely - All-In-One Finance & Business Management designed to help Micro & Small Companies run and manage their business in one place.
HDGraph - HDGraph helps you to free disk space : it finds for you the largest folders on your drive.