ecientemente me topé con la siguiente característica interesante:Instagram iPhone Hooks

Me preguntaba si uno puede abrir una aplicación a través del controlador de interacción de documentos de inmediato,SI tener que mostrar una vista previa (- presentPreviewAnimated :) o una hoja de acción (- presentOpenInMenuFromRect: inView: animated :). Me parece que es la única forma, pero podría estar perdiendo algo.

-(void) saveToInstagram {
    NSURL *url;
    UIDocumentInteractionController *dic;
    CGRect rect = CGRectMake(0 ,0 , 0, 0);
    UIImage *i = imageView.image;
    CGRect cropRect = CGRectMake(i.size.width - 306 ,i.size.height - 306 , 612, 612);
    NSString  *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.ig"];
    CGImageRef imageRef = CGImageCreateWithImageInRect([imageView.image CGImage], cropRect);
    UIImage *img = [[UIImage alloc] initWithCGImage:imageRef];
    CGImageRelease(imageRef);

    [UIImageJPEGRepresentation(img, 1.0) writeToFile:jpgPath atomically:YES];
    url = [[NSURL alloc] initFileURLWithPath:jpgPath];
    dic = [self setupControllerWithURL:url usingDelegate:self];
    [dic presentOpenInMenuFromRect:rect inView:self.view animated:YES];
    [dic retain];
    [img release];
    [url release];
}

- (UIDocumentInteractionController *) setupControllerWithURL: (NSURL*) fileURL usingDelegate: (id <UIDocumentInteractionControllerDelegate>) interactionDelegate {

    UIDocumentInteractionController *interactionController = [UIDocumentInteractionController interactionControllerWithURL: fileURL];
    interactionController.delegate = interactionDelegate;

    return interactionController;
}

- (void)documentInteractionControllerWillPresentOpenInMenu:(UIDocumentInteractionController *)controller {

}