Having passcode for your iPhone 4S prevents unauthorised access of your data. But if you do want to enter passcode and disable passcode feature then you can use the option available as part of iPhone Settings.
Step 1: Press the menu button to access the Home screen.
Step 2: In the Settings screen, navigate General Settings.
Step 3: Scroll down the General Settings screen and tap Passcode Lock option
Step 4: This would display the following Passcode Lock screen. Tap the Turn Passcode Off option and enter the passcode to disable this feature.
Now your iPhone 4S will never display the Passcode and would you to quickly allow access the apps.