ScrollIt is an amazing app that lets you turn your iPad or other iOS device into an LED message display board. The app is pretty straight forward – just type in your message; click on display and voila! – your message will scroll with a very large font, so that every one around you can see it.
The ScrollIt app supports easy-to-type emoticons too, thus adding a lot of fun. Your iPad will beep when the message ends.
If you are using it on an iPhone, it will do a small vibration. It also supports Arabic and Hebrew languages.
You can download it from here. It is free for a limited time.