UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Flexbox Grid - Grid based on CSS3 flexbox
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Carrd - Simple, responsive one-page site creator.
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.
Fabricator - Build your UI toolkit for website design