Petting Zoo by C. Niemann is an interactive picture book that combines hand-made animations with state-of-the-art technology. With over 1 million downloads, this app is a wonderful experience for all ages. It features 21 beautifully animated animals with playful musical sounds that react surprisingly to swiping and tapping. The app is available on the iPhone platform and falls under the Education & Reference category.

The app’s highlight is the quirky animations and the wry humor of acclaimed author and illustrator Christoph Niemann. The app doesn't require any English proficiency, as the animals don't speak English. Petting Zoo is a storybook app that stands out from all others, with its unique approach to storytelling and its charming hand-drawn animations. The app has received high praise from various media outlets, including Wired, USA Today, and The Guardian.