Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
HiOperator - HiOperator is a virtual assistant that answers phone calls, chats with customers, provides in-app help, takes orders, and provides support.
Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.