Tapping the Download Orders button from the "home" screen will allow you to download previously-written orders from the server.
On the screen that appears, you can search by a variety of criteria using the Search By dropdown.
When searching, your results are displayed below the search bar.
Tapping on any order shown will download it to your device, and add it to the Recent Orders screen.
For orders that are older, using the "hamburger menu" (three dots in the top-right corner) will allow you to view much older orders as well by un-checking the Search Recent Orders Only option.