TNKImagePickerController *picker = [[TNKImagePickerController alloc] init];
picker.delegate = self;

UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:picker];
// while this is not stricktly necessary, not including this line will disable taking photos with the camera, pasting images, and selecting all assts in a collection
navigationController.toolbarHidden = NO;

// present the picker as a popover on iPad and landscape iPhone 6+ and a modal sheet on iPhone
navigationController.modalPresentationStyle = UIModalPresentationPopover;
navigationController.popoverPresentationController.sourceView = self.pickPhotosButton;
navigationController.popoverPresentationController.sourceRect = self.pickPhotosButton.bounds;

[self presentViewController:navigationController animated:YES completion:nil];