If your boards are not in dropbox, here's the recommended solution to get your boards from versions 2.4.1 to 3+
Send via Email.
1. Go to the older version of Corkulous and navigate to your board you would like.
2. Click the share button.
3. Select send via email.
4. Select the 3rd item for sending a board.
5. In the next screen, select the first item in attaching to your email.
6. Send the email to yourself. Make sure you can see the email on the same device.
7. In the email you receive, long press the attachment, which will bring up the share manager.
8. Swipe left and select Copy to Corkulous.