You can load your existing DragonSky progress through Google Play Games for Android and Game Center login for iOS.
If you log in with the same Google or Apple account after changing your device, you will be connected to your existing account.
However, both Android and iOS versions have their own game servers. If you’re changing your device from Android to iOS or iOS to Android, you won’t be able to access your existing account.
Data can be lost and recovery is not available if you play with a guest account, so make sure to save your game data with a game account.