UX Flow Wireframe Prototyping System - Create beautiful user flows prototypes for your next project
Supernova Studio - The world’s first true design-to-code platform 🚀
draw.io - Online diagramming application
Anima App - Design, get feedback, convert to code, publish, iterate.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
prototypr.io - Daily design news, inspiration and deals