One of the strangest thing I noticed in the applestore is the presence of a large number of applications to enable the use of the emoticons on the iPhone/iPod/iPad.
It's strange because the emoticon keyboard is present by default in the iOS so I don't know why people downloads this kind of app.
It's very simple to use the emoticons, you have to follow the steps below:
1. Tap the "Settings" App
2. Tap on the "General" item
3. Tap on the "Keyboard" item
4. Tap on the "International Keyboards" item
5. Tap on the "Add New Keyboard" item
6. Tap the "Emoji" item
7. Push the home button
8. Tap on the message App
9. Create a new message, inside the standard keyboard there will be a new button (the world)
10. Tap this button to use the emoticons.