When you have saved the trip, you can go back to it and edit it. You can edit every item on the trip.
For instance you can change the addresses on the trip.
If, during the trip, you didn't have network access and didn't get any addresses you can tap the refresh button, to get the addresses, from the saved locations.
You can also add a place/customer or a car.
if you want to have some additional information you can always add a note, that will show up on the report.