Lottie by Airbnb - Easily add high-quality animation to any native app
Animista - Create beautiful CSS animations in your browser
Marionette Studio - Marionette Studio is an online animation software for beginners and professionals. Animate 2D characters and environments in minutes with no prior skills.
CSS Animation Cheat Sheet - Awesome CSS3 plugin for spiffy animations
Spirit - The animation tool for the web.
Keyframes.app - A timeline editor for CSS animations