WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
SmartWindows.app - Auto arrange all your app windows, whether on one screen or many with a single click!
TreeSize - TreeSize tells you where precious disk space has gone to.
Accelerated - Online community to break into tech & VC
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.
VC Starter Kit - Everything you need to look like a Venture Capitalist