Welcome, and thank you for becoming a member of the King Community!
In the case of Android and I-Phone, your collected booster is stored in a specific location in the application.
This stored booster can not be synced with the server, because the game studio still does not have this process.
You will not be able to transfer the boosters to another device, you will lose the complete booster for app uninstalling or crashing. and the boosters are not refundable.
However, Gold bars and your game progress will be returned, as it has been possible to sync.
