FireScribe (US$0.99) is a cute app for sending something beyond a typical text message. The app creates fireworks against any background you choose, then spells out your custom message in pyrotechnics, letter by letter.
You start be selecting a background. It can be from your camera roll, Facebook, or from a gallery included with the app, or you can take a fresh photo from within the app.
Type your text, and then the app will render the video. From there it saves it to your camera roll for sending via email or Apple Messages. The videos are pretty compressed and are 12-15 seconds in length.