chose whether you want to store your backups on the device or on iCloud. If you backup to your devices internal memory, you can transfer the backup file via iTunes (device symbol upper left corner->File Sharing->Kana LS) to you PC/Mac and from there to other devices.
Restore selected Backup (current data on device are overwritten)
Create a new Backup
Delete selected Backup
If you used Dropbox in the previous Versions of the app (<3.0): Here you find instructions how to transfer these old Dropbox Backups