If your files are saved to a cloud storage connection, like Google Drive, they'll be there when you create that same connection in iAnnotate on your new device. If they're saved to Local Files, you'll want to use iTunes File Sharing or copy them to a cloud server.
To use iTune File Sharing follow these steps:
Here are the steps to copy files to iTunes File Sharing from version 3:
1. Tap the files/folders you would like to move (so that a check appears in the circle)
2. Tap "actions"
3. "send to iTunes"
4. Connect your iPad/phone to the computer with a cable, like you would to sync the devices.
5. Now from the computer: select the finder icon
6. Find your device on the left side and select it.
7. Select "files" then "iAnnotate PDF"
8. Select the files you wish to save and move them to the desired location.
Copy to iTunes File Sharing or Cloud Connection in iAnnotate 4:
1. Tap the files/folders you would like to move (so that a check appears in the circle)
2. Tap "..." at the bottom of the screen
3. Select "copy to..."
4. Select the location you want to copy the files to.
If you chose iTunes
5. Now from the computer: select the finder icon
6. Find your device on the left side and select it.
7. Select "files" then "iAnnotate PDF"
8. Select the files you wish to save and move them to the desired location.
If you chose a cloud server you will only need to add the cloud connection to the new device.