A custom inputView that accepts Morse Code. Inspired by the Gmail Tap April Fools Joke. You can actually set this as the inputView for any UIKeyInput or UITextInput compliant view (e.g. UITextField) and then the user can use Morse Code for input instead.
Improvements welcome! For example I was thinking about a nice dynamic table that would show the combinations that are still possible with the current input. Also I couldn't find a good image to use for the button.