UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Uxcel - The easiest way to learn UX/UI design
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
UX Challenges - Done reading about UX? Start doing it.
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.
UI Coach - Become a better UI designer in 30 days