gistfile1.m

-(BOOL)appIsPresentInLoginItems
{
    NSString *bundleID = @"blah";
    NSArray *jobDicts = (__bridge NSArray *)SMCopyAllJobDictionaries( kSMDomainUserLaunchd );
    
    NSPredicate *predicate = [NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
        return [[evaluatedObject valueForKey:@"Label"] isEqualToString:bundleID] && [[evaluatedObject valueForKey:@"OnDemand"] boolValue];
    }];
    
    return [[jobDicts filteredArrayUsingPredicate:predicate] count] >= 1;
}

gistfile2.rb

HELPER_BUNDLE_ID = 'blah'

def launchesAtLogin?
  SMCopyAllJobDictionaries(KSMDomainUserLaunchd).any? do |job|
    job['Label'] == HELPER_BUNDLE_ID && job['OnDemand']
  end
end