Children's Audio Book for ios and android - App project

Mobile app project description

The main feature of this app is an audio book. There would need to be a feature to purchase a physical product via amazon. We would want it to have similar features to https://itunes.apple.com/us/app/the-monster-at-the-end-of-this-book-starring-grover/id409467802?mt=8. We would like side fly-ins for features that include purchases, social media, and additional info including contact. We have artwork, graphics and verbiage already created. As you are the experts please tell me what I am missing. If you have read this description and have similar apps please send links to the apps. Thank you.