Actually, he's wrong on that point. there is a way to force quit an app without saving its state.
Press and hold the sleep/wake button for several seconds, until the Slide to Power Off control appears. Release the sleep/wake button and hold down the Home button for another 7-10 seconds.
The app will quit and return the user to the Home Screen.
https://squareup.com/help/en-us/article/5125-square-stand-su...