Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Mindmapper - Be more creative and get more done. Process your thoughts with a mind map and implement with a planner.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.
ARIS Express - ARIS Express is based on the proven ARIS methodology and industry standards.
mind42 - Mind42 is a free online mind mapping software.