Lucid+Chart

Lucidchart: Online tool to create flowcharts, mind maps, Venn diagrams, and many other types of diagrams. It can be used for free for education and integrates with Google Apps. Free demo at http://www.lucidchart.com

The same company offers Lucidpress for free to create newsletters, flyers, brochures, presentations and more. Free demo at http://www.lucidpress.com