Sharing image using UIActivityViewController

Just create a button and it's action. And install the button's action like this.

Note: You have to log in your facebook or twitter by going to setting. Then do like this.

@IBAction func onShareTouched(sender: AnyObject) {

    print("share")

    let myShare = "My beautiful photo! <3 <3"
    let image: UIImage = UIImage(named: "yourImageNameHere")

    let shareVC: UIActivityViewController = UIActivityViewController(activityItems: [(image), myShare], applicationActivities: nil)
    self.presentViewController(shareVC, animated: true, completion: nil)

}

let activityItem: [AnyObject] = [self.imageView.image as! AnyObject]

let avc = UIActivityViewController(activityItems: activityItem as [AnyObject], applicationActivities: nil)

self.presentViewController(avc, animated: true, completion: nil)

Note : The above code tested in Xcode 6.3 simulator