This app was mentioned in 2 comments, with an average of 1.00 upvote
I still use it.
But mostly because it's a bit easier to remember than CSS transitions and they support onclick etc so you can make a legitimate game without JS.
Also, my main tool has zero support for CSS3 animation as of time of writing
PNG version for browsers that have support issues (permalink)
All of these are permanent. ^(except the first PNG)
These were all created using a tool on my phone called Simplector.
There's a demo here, but it's well worth the $5 AUD in my (personal) opinion.