Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Visual Understanding Environment - Visual Understanding Environment (VUE) is a mind-mapping and concept-mapping tool.
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
FreeMind - FreeMind is a premier free mind-mapping software written in Java.
LightShot - The fastest way to take a customizable screenshot.
Flying Logic - Highly visual software for planning support used by strategists, process improvement specialists, teachers, and writers. Windows, Mac OS X, and Linux.