I happen to come across this small game for kids on the apple store. It is called touchsmash.
This game operates by finger touches. Initially, the iphone screen will be blank when you start the game. Once you touch the screen, random pictures will pop up and different funny sounds will appear with each touch. As the pictures pop up, the older pictures gets cleared to make way for new ones. Thus, it is not that boring.
If you got a crying niece or nephew, I believe this app will distract them and make them smile again. Simple yet effective if you are tasked to babysit them.
Get it here on itunes. It is only $0.99. Make your niece or nephew happy.