Back up and move to a new computer

A backup is one .zip file holding the whole Journey: every picture, recording and note, and the catalog. It opens with any zip tool.

Back up

Go to Settings › Back up and restore.
Click Back up this Journey… and choose where to save it.
Click Show the backup to find the file. Keep a copy on a USB drive or another computer.

Move to a new computer

Install the app on the new computer (Installing).
On the first screen, click restore a backup (or, later, Settings › Restore a backup…) and pick the .zip file.
Click Open the restored Journey.

A backup and an export are different: the export is the family history to read and share; the backup is what you need to keep working on it.