Google Authenticator works with 2-Step Verification for your Google Account to provide an additional layer of security when signing in.

With 2-Step Verification, signing into your account will require both your password and a verification code you can generate with this app. Once configured, you can get verification codes without the need of a network or cellular connection.

Features include:
- Automatic setup via QR code
- Support for multiple accounts
- Support for time-based and counter-based code generation

To use Google Authenticator, you need to enable 2-Step Verification on your Google Account. Visit http://www.google.com/2step to get started.