How can I export the entire app so I have a backup in case?

How can I export the entire app so I have a backup in case?

I am sure I have come across this in the interface but maybe getting confused with some other aspect of the app. Could you tell me how to make a backup 'export' of the app in case I need to upload a copy in case of disaster or just to make a point in time copy in case I break my application?