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n the case of Android and I-Phone, your collected booster is stored in phone storage.
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.
Your stored boosters may have been lost for app crashing on your device.
Here are some tips for not/less facing this kind of problem in the future,
Make your device software auto update.
Make your game app auto update.
Don't open game when battery below 25%
Don't accept incoming call when you playing this game.
Close all background running app before start this game.
Make free device internal memory up to 2 GB
Keep RAM free.