When you no longer want an app on your iPhone 4 you should be able to quickly delete it. Here are the steps to follow:

  1. Go to the icon of the app you want to delete and hold your finger on it until the icon begins to shake.
  2. Look for the “X” in the upper left hand corner of the app to delete it.
  3. Choose the home button on your iPhone 4 after the app is deleted to stop the icons from shaking.

If these steps don’t work, double press the home button. When the line of apps come up, scroll left to right until you find the app you want to delete and press the red “no entry” button. Then repeat the first three steps.

Source: eHow