Password Protect your Projects
You can now password protect your website project file in Thundersite. Once a password is set, anyone who tries to access the website project will be required to enter the correct password.
Menu: Website > Protect with a password...

Please note: This feature is not compatible with earlier versions of Thundersite. Do not set a password in Thundersite if you will be sharing your website project file with someone using an earlier version of Thundersite. Alternatively you could place the unprotected file into a ZIP archive, and add a password to the archive using a program like WinZip.