- Open the Settings application on your device.
- Select Mail, Contacts, Calendars.
- Select Add Account...
- Select Other
- Select Add CardDAV Account
- Fill out your account information in the following fields: 
 Server: Enter "google.com"
 User Name: Enter your full Google Account or Google Apps email address.
 Password: Your Google Account or Google Apps password.
 Description: Enter a description of the account (e.g. Personal Contacts).
- Select Next at the top of your screen.
- Make sure that the "Contacts" option is turned to ON.
After you've completed setup, open the Contacts app on your device, and syncing will automatically begin.