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
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
UX Challenges - Done reading about UX? Start doing it.
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Weekly UX Exercise - Receive challenges top companies use to interview designers