How Do I Share My WordBoard Keys?
There are two ways to get your WordBoard keys onto another device: Cloud Backups for your own devices, or sharing a file with someone else.
Your own devices
Use Cloud Backups: on the other device go to More → Cloud Backups, pick a backup and tap Merge Backup. Full steps: How do I back up and restore my keys with Cloud Backups?
Sharing with someone else
To share a single key or a folder (images included), tap Edit on the Keys tab, then the share icon on the key or folder.

To share all your keys, go to More → Share Keys With A Friend. This doesn't include images.
The other person opens the file and chooses WordBoard. Importing needs WordBoard Pro.