WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Muzzle - Silence embarrassing notifications while screensharing
TreeSize - TreeSize tells you where precious disk space has gone to.
Upscope Screen Sharing for Intercom - No-downloads screen sharing fully integrated with Intercom.
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.
Dead Simple Screen Sharing - Simple screen sharing and audio conferencing software.