Bunnymator, or impractical computer vision

This is a story of an old toy webpage that used to entertain kids with hand-drawn animated doodles.
Disclaimer: I’m not a computer vision expert, so many of the mistakes might be obvious to the reader, but nevertheless are part of my story.
I vaguely remember that in the early days of smartphones there was an app that allowed you to print a grid of squares. Then you scribbled some hand-drawn animated frames in each cell.