Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
Mindomo - Easy-to-create and share mind maps, concept maps, task maps and outlines. Mind mapping software for Web, Desktop, iOS and Android. Mind map with us for free!
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.