An insanely simple way to create CSS animations
Keyframes gives you a visual timeline to help you create, view, and run animations without having to go back and forth between your browser and editor.
And it gives you the CSS when you're done.
Extension
With the extension, the UI gets injected right on top of any website you want (even local projects) and you get to choose the element you want to animate.
Web App
You can also use the web app which gives you a canvas and lets you create animations on a specific element that you can customize with your own CSS.