Moqups is a streamlined and intuitive web app that helps you create and collaborate on wireframes, mockups, diagrams and prototypes for any type of project.
License: Freemium
Fluid UI is best for quick prototyping with its intuitive interface and real-time collaboration, while Moqups offers more versatility with design and project management tools. Both tools cater to different needs: Fluid UI focuses on rapid prototyping, whereas Moqups is more suited for comprehensive design workflows.