I saw this website: http://nippongrammar.appspot.com/
I saw that its Github project was released on an MIT license.
I adapted it into a userscript for Wanikani: https://greasyfork.org/en/scripts/12034-wanikani-nippongrammar-extension
Now with hotkeys:
- Shift + left/right to switch between original and strokes.
- Click on the strokes to make it play again.
Pictures of it in action:
Note: Depending on your internet connection, it might take a while to load, and there is currently no indication whether it is loading at all.
I will look into it for the next update, but I don’t know when that will be.