No, the app's source code will remain the same.

Mopapp works by importing raw sales data from the notification emails sent by the store, or from the store's CSV reports. What is required to make the process work, if you want to take advantage of the daily automatic data import (instead of just manually importing the CSV from time to time) is the sets of credentials to access your mailbox or store control panel, so that Mopapp can find and process the order notification emails, and/or automatically request and download the updated CSV files.

More info: I don't want to give you my mailbox credentials...any alternative?