Instead of typing in a password, Android™ 4.0 users can simply use their face. Here’s how, as seen on an HTC One™ X.
1. Go to Settings and select Security.
2. Under Screen Security, click Screen Lock. From the list of options available, choose Face Unlock.
3. Follow the on-screen instructions for taking a photo of your face using your phone’s front-facing camera. Extend your arm with the phone’s screen facing you until the image of your face on screen is completely within the dotted lines. The phone will snap a photo of your face and show a check mark as confirmation. Hit Continue.
4. Make sure to choose a backup method of unlocking your phone. If your environment is too bright or dark, or if your phone is unable to recognize you, you will be prompted to input your backup code. You can elect to draw a pattern or simply type in a four-digit code. Whichever you choose, follow the on-screen instructions and then hit Continue.
5. Once you create your backup code, you can go test that your face password is working correctly. Click the power button, drag the on-screen unlock “ring” as you normally would, and hold the phone within range of your face. The camera will flash briefly to confirm your face before unlocking the phone.