A free program for Android, by av.co.

Voice Screen Lock: Unlock Screen With Voice Command is a smart and useful application which allows you to unlock your smartphone using voice commands. It also provides you with an option of a password screen to further secure your phone from unwanted access by others.

This application works on Android devices.

Once you start the app, you will be required to enable the microphone.

After that, you can begin using this application by speaking to unlock your device.

Once you are finished speaking, the app will respond with the command you have spoken.

The application will then display the password screen which you have set.