The Pauli & Friends book series is designed and developed according to a multi-level discovery concept and is suitable for ages 0 to 5 years. Younger children will enjoy the illustrations and squeaker while toddlers will be entertained by the hidden pictures that come to life when bathed in warm water. Young children will have fun interacting through the included app download. Books in this series include: Pauli and Sea Friends Pauli and Circus Friends Pauli and Space Friends