Yes, you can a different app to use as your Marketing App.
This is a change the StickyApps team will need to do for you.
To change or update the app you would like to use as your Marketing App, email support@getstickyapps.com and let us know the name of the app you would like to use as your Marketing App.
This will change the status of your existing marketing app to Public App (a paid app). If you do not want your former Marketing App to count toward your total number of Public Apps, change its status to Private App.