A baby game for Android
This app will show a small piano a baby can use to explore sounds in a mobile device. At the same time, it will block any naive attempts at closing the app. The back, home and apps-menu buttons will be blocked, and Android's top menu won't be available.
This ensures a baby can't accidentally close the game, preventing any actions on the device you may not want.
Grown ups can unlock the app by touching the settings icon with one finger, then holding the second setting icon with another finger.