Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Kalam Labs - Twitch for Science
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
RunaWFE - RunaWFE Free is a free Open Source BPMS (business process management system), which serves to optimize and automate business processes (for Windows, Linux, Mac OS).
ARIS Express - ARIS Express is based on the proven ARIS methodology and industry standards.
Littlecodr - Insanely fun card game that teaches kids the basics of code