StoryStarling
I'm working on StoryStarling (https://www.storystarling.com). It creates custom hardcover children's books from scratch around any idea, instead of swapping names into pre-set templates. We mostly focus on things you cannot find in bookstores: bilingual stories with parallel text for multilingual homes, and non-fiction for kids who have hyper-specific obsessions (like tunnel boring machines or wastewater systems).