Redboard - High-end 3D storyboarding software for animation production workflows.
OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Storyboarder - Storyboarder makes it easy to visualize a story as fast you can draw stick figures.
Synfig Studio - Just another WordPress site
Plotagon - This app, Plotagon. is very fun. Creative and lets me express my ideas and all of my desiors!
Blender - Blender is the open source, cross platform suite of tools for 3D creation.