Lucidchart: a free collaboration tool for teachers
Eliza Wright, A GeekyMomma's Blog, January 11, 2013.
I've been using draw.io to make flowcharts for gRSShopper - it's pretty basic, and doesn't share the way I'd like it to, but it's free. Draw.io was set up to demonstrate the mxGraph Javascript diagramming library and works quite well as a drawing tool. You can find it on GitHub. Here's more on the plug-in. Here's where I tried to share a drawing using Google Drive (also pictured above). More...