UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Abstract - A secure, version-controlled hub for your design files
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Kactus - Design version control without changing your tools
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Git Sketch Plugin - Version control for designers