Question: I have an iphone app nearing completion that does not support 3.5 inch screens.

Do all apps have to support iphone/ipod versions 4 and below? Do I need to modify my app?

To be more clear, I want to know whether my app is likely to be rejected if it does not support 3.5 inch displays.

Answer: 
It sounds as though you're looking for a **singleton** class. Here's a thread safe pattern for one:

**Interface**

```
@interface MYSingeltonClass : NSObject

+ (MYSingeltonClass *) sharedManager;

- (void) doSomething;

@end

```

**Implmentation**

```
@implementation MYSingeltonClass

+ (MYSingeltonClass *) sharedManager
{
    static MYSingeltonClass * sharedManager = nil;

    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedManager = [[MYSingeltonClass alloc] init];
    });

    return sharedManager;
}

- (id)init
{
    self = [super init];
    if (self) {
    }

    return self;
}

- (void) doSomething
{
}    
@end

```
1) Use Singleton design Pattern
You will have 1 object usable everywhere via a [MyClass sharedInstance]

2) Create an "helper" : a class with only class methods +(...*)... instead of -(...*)....
You will not have any object, just a boundless of methods (don't use this if you need properties)