Atomic

Atomic is a browser-based prototyping platform that emphasizes micro-interactions and motion design. Designers import images or sketches, then define triggers and transitions for elements. A timeline editor helps tweak easing curves, durations, and object states. Collaboration features let teams comment or propose changes. The system also tracks versions, so you can roll back if needed. While advanced features require a paid plan, Atomic’s free tier accommodates basic prototypes, letting small teams produce interactive UI concepts with stylish animations for web or mobile apps.