Yes! - Within Natural HR, there is the ability to log in to your user account using an email address which is hosted within Google Mail. 

In order to set this up, you must first ensure that an email address is a valid email address with Google Mail. 

Setting up Google Single Sign on

To enable Google single sign on from within an administrator-level account, you will need to go to:

 Administration -> Company -> Settings -> Security settings 

Make sure that the "Allow Google login" field is set to 'Yes'.

Once submitted, you will need to make sure that the user name for the employee's user account is set to using the google-registered email address. If you want to update the employees work email address to the login email, tick the "Update employee work email address" tick box.

People -> Users

Then locate the user you'd like to update and click Actions -> Edit.

Once submitted, on the login page you will need to select the Login with Google button as opposed to entering the username and password to access the system.