Flowchart.com - Online real time collaboration Flow chart software service.
asciiflow - Infinite ASCII diagrams, save to Google Drive, resize, freeform draw, and export straight to text/html.
Calamari - Calamari helps organizations, companies, and enterprises to manage their human resources in an easy and compliant way by delivering modern and easy-to-use time tracking and attendance management tools.
Lekh Diagram - Lekh Diagram empowers you to express your idea on iPad and iPhone simply by sketching shapes with...
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Core2D - A multi-platform data driven 2D diagram editor.