Useful utility method to get the most appropriate image resource from the main bundle for the device based on filename. Fills a need until the new asset packages in Xcode 5 is released.

gistfile1.m

+ (UIImage *)imageResource:(NSString *)name ofType:(NSString *)type {
    
    NSString *systemVersion = UIDevice.currentDevice.systemVersion;
    NSString *iOSMajorSystemVersion = (systemVersion.length) ? [NSString stringWithFormat:@"iOS%@", [systemVersion substringToIndex:1]] : @"iOS";
    
    if (UIScreen.mainScreen.bounds.size.height == 568.0f) {
        /* iPhone 5 */
        NSString *iPhone5SystemVersionImageName = [NSString stringWithFormat:@"%@-%@-568h@2x", name, iOSMajorSystemVersion];
        NSString *iPhone5SystemVersionImagePath = [NSBundle.mainBundle pathForResource:iPhone5SystemVersionImageName ofType:type];
        
        if ([NSFileManager.defaultManager fileExistsAtPath:iPhone5SystemVersionImagePath])
            return [UIImage imageWithContentsOfFile:iPhone5SystemVersionImagePath];
        
        NSString *iPhone5ImageName = [NSString stringWithFormat:@"%@-568h@2x", name];
        NSString *iPhone5ImagePath = [NSBundle.mainBundle pathForResource:iPhone5ImageName ofType:type];
        
        if ([NSFileManager.defaultManager fileExistsAtPath:iPhone5ImagePath])
            return [UIImage imageWithContentsOfFile:iPhone5ImagePath];
    }
    
    if (UIScreen.mainScreen.scale == 2.0) {
        /* Retina */
        NSString *retinaSystemVersionImageName = [NSString stringWithFormat:@"%@-%@@2x", name, iOSMajorSystemVersion];
        NSString *retinaSystemVersionImagePath = [NSBundle.mainBundle pathForResource:retinaSystemVersionImageName ofType:type];
        
        if ([NSFileManager.defaultManager fileExistsAtPath:retinaSystemVersionImagePath])
            return [UIImage imageWithContentsOfFile:retinaSystemVersionImagePath];
        
        NSString *retinaImageName = [NSString stringWithFormat:@"%@@2x", name];
        NSString *retinaImagePath = [NSBundle.mainBundle pathForResource:retinaImageName ofType:type];
        
        if ([NSFileManager.defaultManager fileExistsAtPath:retinaImagePath])
            return [UIImage imageWithContentsOfFile:retinaImagePath];
    }
    
    NSString *standardSystemVersionImageName = [NSString stringWithFormat:@"%@-%@", name, iOSMajorSystemVersion];
    NSString *standardSystemVersionImagePath = [NSBundle.mainBundle pathForResource:standardSystemVersionImageName ofType:type];
    
    if ([NSFileManager.defaultManager fileExistsAtPath:standardSystemVersionImagePath])
        return [UIImage imageWithContentsOfFile:standardSystemVersionImagePath];
    
    NSString *standardImagePath = [NSBundle.mainBundle pathForResource:name ofType:type];
    
    if ([NSFileManager.defaultManager fileExistsAtPath:standardImagePath])
        return [UIImage imageWithContentsOfFile:standardImagePath];
    
    return nil;
}