How to implement an extra view for a game when it starts or gets interrupted

I want to implement a view on which has "resume", "save" and "quit" buttons and it popups when the game is started or interrupted. I looked up a few books and most just mentioned animation of view's transition or suggested using tab bar controller, etc and all these are not applicable to my game's need. I would like to know:

1) How to implement it? Such as how to declare, how to call and and where it is called? Just create another ViewController class with .xib file? Then what? Just add it as 开发者_运维技巧a subview to window in delegate file like [window addSubview:viewController.view];?

2) How to make it appear after the startup intro screen and before the game starts?

3) How to make it appear on top of the game when the game is paused?

4) How to make it disappear when it is resumed?

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I would create a separate view controller and display it with -presentModalViewController:animated:.