New children’s storybook app The Terrifying Building in Eyeville tells the tale of a town afflicted by a builder named Kanser.

“He quickly gets to work building in Mr. Nice’s house and is basically impossible to stop,” explains its App Store listing. “Kanser builds and builds, and after a short time, his dreadful building has spread to every corner of the town.”

You’ve probably spotted the metaphor by now, thanks to our headline. Author Joel Grøndrup’s story is aiming to be a way to explain cancer to children aged four and up.

“This isn’t a perfect allegory for the nature of cancer, and the goal is that the child won’t even realize that the story is about the illness,” the listing goes on.

“In this way, it’s up to parents to explain what the story can represent. Thus, the story also works as a good children’s story.”

Joel was inspired to write the book when his own daughter was diagnosed with a rare form of cancer called retinoblastoma when she was just one year old.

We think the app will be invaluable for any parent grappling with the challenge of explaining cancer to a child – whether the child has it or an adult that they know.

The Terrifying Building in Eyeville costs 69p on the App Store, and runs on iPhone, iPad and iPod touch.