For example I have a game with a menu screen and then I have the game itself. I want the timer disabled whilst playing the game but enabled when in the menu screen. I currently have the following code in my app delegate that disables the timer:
application.idleTimerDisabled = YES;
Any help would be appreciated.
Just set it to NO when you show the menu. You can enable and disable the timer as you like, with the code you show.
If you can do it in your app delegate, why wouldn't you be able to do it from anywhere else? The only question is how to get a reference to application:
[Application sharedApplication].idleTimerDisabled = NO;