Houghton Mifflin Harcourt’s award-winning Curious World app is full of educational games, videos, and books, with new content updated weekly. We’ve made over 70 games to date for the app ranging between puzzles, vocabulary builders, and math activities to provide engaging early learning opportunities to preschoolers. Built in HTML5 for deployment in an app wrapper, the games explore a wide variety of visual styles and illustrations to give each game a fresh look for every app update.