check ios app is first launch

gistfile1.txt

#define LAST_LAUNCH_VERSION_KEY        @"last_launch_version_of_application"

- (BOOL)isFirstLoad
{
    NSString *currentVersion    = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
    NSUserDefaults *defaults    = [NSUserDefaults standardUserDefaults];
    NSString *lastLaunchVersion = [defaults objectForKey:LAST_LAUNCH_VERSION_KEY];
    
    if (!lastLaunchVersion || ![lastLaunchVersion isEqualToString:currentVersion]) {
        [defaults setObject:currentVersion forKey:LAST_LAUNCH_VERSION_KEY];
        [defaults synchronize];
        return YES;
    }
    
    return NO;
}