Conceptboard
Browser-based visual collaboration.
GroupMap
Browser-based ideas/mapping.
Process On
Web-based diagram tool.
Spacedeck
Visual collaboration for teams.
Murally
Browser-based, collaborative whiteboards.
Trello
Flexible, browser-based collaborative organising and project management.
Touchpoint Dashboard
http://www.touchpointdashboard.com
Web-based journey mapping tool.
Omnigraffle
http://www.omnigroup.com/products/omnigraffle/
Diagramming and wireframing app for Mac and iPad.
smap.ly
Web app for mapping stakeholders, service systems and service processes.