UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:@[@"link"] applicationActivities:nil];

if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_7_1) {
    activityViewController.popoverPresentationController.sourceView =     self.buttonShare;
}
[activityViewController setValue:@"Subject" forKey:@"subject"];
activityViewController.view.tintColor = [UIColor blueColor];
[self.navigationController presentViewController:activityViewController animated:YES completion:^{ }];