DevShop allows you to password protect your sites with an "HTTP Password".
This prevents anyone (including search engines) from accessing any page unless they know the password.
To add a HTTP Password to an environment:
Visit the Project Dashboard.
Click an environment's Environment Settings icon icon.
Click Environment Settings.
Scroll toward the bottom of the form.
Look for the section HTTP Basic Authentication.
Enter a username and password, and a message if you wish.
Wait for the environment to complete verification.
Visit the site and confirm that the browser asks you for a username and password.
To remove the password, simply empty the "username" and "password" fields from the environment settings form.