1. WireframeSketcher is a wireframing tool for creating wireframes, mockups and prototypes for desktop, web and mobile apps. It's a desktop app for Mac, Windows and Linux, and a plug-in for any Eclipse IDE.

  2. The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project

  3. The prototyping tool designers have been waiting for.

  4. Balsamiq. Rapid, effective and fun wireframing software.

  5. A powerful animation and prototyping application for Mac & iOS.

  6. A rapid prototyping, design collaboration and handoff tool

  7. Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.

  8. Professional digital design for Mac.

  9. Create fully-interactive high-fidelity prototypes in minutes that look and work exactly like your app should. Sign up for a free 15-day trial and get started.

  10. Free vector graphics editor. A simple yet powerful web and desktop cross-platform tool for everyone.

  11. Mockup a live website to a mobile device

  12. Free Online Vector Editor - Design and customize SVG illustrations and graphics quickly and easily in your browser.