Using this API call you can download the underlying spreadsheet of your app - and of course - also automate this in a script.
This becomes especially useful when you have read-write apps where your users can edit the app spreadsheet by themselves, e.g. by editing the lists in the app.
API Token required
This call requires an API Token for authentication.
Go to /user/apiTokens to create one. You need to supply the generated token in the
Authorization: Token <ApiToken>header to authenticate your account when using this API call.