The Konami Code is a sequence of button presses and control movements used to unlock cheats and easter eggs in many Konami (and other) games starting in the mid-80’s.
Danny Riccioti has created a source code l allowing you to recognize the original Konami Code (up, up, down, down, left, right, left, right, a, b) through gestures on iOS devices. It could make for a pretty cool way to unlock easter eggs and cheats, and provides a nice example on creating a gesture recognizer.
With some tweaking you can adjust it to recognize other gesture sequences, and there are action methods so you can provide visual feedback to users entering the code, and a virtual NES control shows up so the user can press the buttons.
You can find the example on Github here.
A fun little code example that really makes me wish I had an NES and Contra.