Is it possible to access data across 2 different iOS apps?

Question

Let's say that I store some ID data in App1 and want to access it in App2 on the same device. Is this possible on the platform? Are there any workarounds for this if not?

Answer 1

You can use the iOS keychain. Here's a good tutorial on keychain access groups.

Answer 2

Image Share Between My app to Instagram:

NSURL *instagramURL = [NSURL URLWithString:@"instagram://location?id=1"];
if ([[UIApplication sharedApplication] canOpenURL:instagramURL]) {
    NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"Image.ig"];

    NSData *imageData = UIImagePNGRepresentation(originalImageView.image);
    [imageData writeToFile:savedImagePath atomically:YES];        
    NSURL *imageUrl = [NSURL fileURLWithPath:savedImagePath];

    UIDocumentInteractionController * docController = [[UIDocumentInteractionController alloc] init];
    docController.delegate = self;
    [docController retain];
    docController.UTI = @"com.instagram.photo";
    [docController setURL:imageUrl];
    [docController presentOpenInMenuFromRect:CGRectZero inView:self.view animated:YES];
}