iWonder AR is a free Android application developed by Express Publishing. It is an AR (augmented reality) application that complements their English language learning books. By scanning the pages of the book with the app, users can access interactive AR content, watch videos, and play with Rolo, the robot character.

The AR content in iWonder AR is engaging and interactive, making language learning fun and accessible. The videos provide additional context and examples for the vocabulary and grammar presented in the book. The app also allows users to take pictures with Rolo and share them on social media.

Overall, iWonder AR is a great way to enhance the learning experience for students using Express Publishing's English language learning books. The app is easy to use and provides a fun and interactive way to practice English language skills.