What happen if I switch my device between iOS and Android?

Since your account is automatically linked to your Google Play account or Apple’s Game Center account, once you switch between these platform, you will not be able to auto-cover your old progress.  Before migrating to a new device, we recommend you create a migration code.  Go to the “Setting” menu and click on “Link Device” to create a migration code.  You can use this code to recover your game progress on your new Device from the “Setting” menu again later.