Question: How to implement a button above the keyboard? (For example: "Notes" app, or
[like this](http://i.stack.imgur.com/hrLlq.gif)

Answer: 
MKaro's solution works! I'll attach the Swift 3 version for faster copy-paste.

**Swift 3:**

```
let keyboardToolbar = UIToolbar()
keyboardToolbar.sizeToFit()
keyboardToolbar.isTranslucent = false
keyboardToolbar.barTintColor = UIColor.white

let addButton = UIBarButtonItem(
    barButtonSystemItem: .done, 
    target: self, 
    action: #selector(someFunction)
)
addButton.tintColor = UIColor.black
keyboardToolbar.items = [addButton]
textView.inputAccessoryView = keyboardToolbar

```
Its simple, all you need is to use UIToolBar and UIBarButtonItem.

Here is a simple example, that make "Special Keyboard" for specific TextField:

This code create the toolbar:

```
UIToolbar *keyboardToolbar = [[UIToolbar alloc] init];
[keyboardToolbar sizeToFit];
keyboardToolbar.translucent=NO; //if you want it.
keyboardToolbar.barTintColor = Some Color; //the color of the toolbar

```

this code create the button that you want

```
UIBarButtonItem *doneBarButton = [[UIBarButtonItem alloc]
                                  initWithBarButtonSystemItem:UIBarButtonSystemItemDone
                                  target:self.view action:@selector(set your own function here:)];
[doneBarButton setImage:CHOOSE YOUR IMAGE];
keyboardToolbar.items = @[doneBarButton];//you can add couple of buttons if you want to.
yourtextfield.inputAccessoryView = keyboardToolbar;

```