Don't stop there — you've got a ton of handy apps loaded on your smartphone, but some of them also contain sensitive info (banking apps, for example). Don't let your cell go unprotected — password-protect your home screen so hackers can't access your private info if lost or stolen.
From the home screen, select Settings > General > Passcode Lock
From the home screen, choose Settings > Security > Screen lock and set an alphanumeric password for your home screen.
From the home screen, select Options > Security Options > General Settings > Password > Enabled