Easy Music aims to help kids 5 to 8 years old to learn the basics of music. Target platform is iOS but we made an Apple TV version and an Apple Watch extension for iPhone where the parent can play drum on it along with the child. The game made it to the front page of the App Store on the top banner all over the world and was made Editor's Choice.
It's made with Unity3D. I was not the main programmer on the project but I helped with fine tuning for about two months. I was also the one responsible for the Apple Watch extension.
Try it, it's available on Google Play and on the Apple App Store.
