UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
RemoteHQ - Real-time collaboration for distributed teams
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Terrastruct - A diagramming tool for software architecture
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Diagrams for Mac - A diagram editor for visualizing structures and processes