To load saved gang sheets from earlier click the account button in the top right of the screen (if you are not logged in it will say unknown).
A drop down will appear, click on "My Designs" this will bring up your prior saved gang sheets by size. Select all to view all prior saved gang sheet if you don't remember an exacted size.
*Note gang sheet are only saved if you hit the saved button. Also they are saved to your account and the computer you are using. So it advised to be logged in to your account while using the builder.