If the home app is not working try to do a hard reset by holding the power button and the home button. Or go to the settings then general and then reset. If the home button its self is not working you may have to replace it or bing it to a repair storage.
More details. What are you doing, what happened before this occured?
из Cameron
Is the home button not working or the home app
из Mohammadali Khalifa
The home button.
из carolyneslick.ce