Clipdrop - Create stunning visuals in seconds
Animista - Create beautiful CSS animations in your browser
Shortcuts.design - Every shortcut for designers in one place!
CSS Animation Cheat Sheet - Awesome CSS3 plugin for spiffy animations
MyPopClip - The most basic feature of MyPopClip is to select a text with the mouse to do the copy and paste action, saving us the usual Command+C or V trouble, but the real power of this tool lies in the use of its extensions.
Keyframes.app - A timeline editor for CSS animations