Once you have set all the design features of your App, you can save it as a 'theme' - this means that you will able to use the same design options for another app, whenever you want, as it will be saved under the category 'my themes'.
To save your app as a new theme, click on the Modify button of your App from the App list on your dashboard:
Then click on the Look & Feel tab from the top Menu:
and on Theme from the left hand side menu:
Click on the Add New Theme tab, insert a Name for your theme and upload a preview image:
You can also upload a file from your computer.
Click on Save as File to add the theme to your computer, and on Add to my themes to add it to the your list of themes on the dashboard.