Animista - Create beautiful CSS animations in your browser
Zen Flowchart - The simplest tool to create flowcharts
CSS Animation Cheat Sheet - Awesome CSS3 plugin for spiffy animations
Octopus.do - Build your website structure in real-time and rapidly share it to collaborate with your team or clients. Start prototyping websites or apps instantly.
Keyframes.app - A timeline editor for CSS animations
Scheme Flowcharts - A huge pack of layouts for UX prototyping