bypassing UIImage caching.m

@implementation UIApplication(Retina)

- (BOOL) deviceIsRetina
{
    if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] == YES && [[UIScreen mainScreen] scale] == 2.00) {
        // RETINA DISPLAY
        return YES;
    }
    else
    {
        return NO;
    }
}

@end

@implementation UIImage(Retina)

+ (UIImage *)imageNamed:(NSString *)name
{
    if([[UIApplication sharedApplication] deviceIsRetina])
    {
        NSArray *file = [name componentsSeparatedByString:@"."];
        
        NSString *retinaName = [NSString stringWithFormat:@"%@@2x", [file objectAtIndex:0]];
        
        return [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:retinaName 
                                                                   ofType:[file objectAtIndex:1]]];
    }
    else
    {
        NSArray *file = [name componentsSeparatedByString:@"."];
        return [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[file objectAtIndex:0] 
                                                                   ofType:[file objectAtIndex:1]]];
    }
}

@end