I hade lot of boosters that I collected during my 6-7 years. Today I reinstalled the application in my iPhone and realised that every are gone but my golds. Please advise!
Hello @peyz and welcome to our wonderful community. I am so sorry that happened to you. However any lives and boosters are saved locally to the device you play on so if you transfer to a new device or de-install and reinstall the game on the same device - all those boosters and lives will be gone.
What happens is when you de-install the game you are clearing the memory of what was stored locally with that game and when you re-install the game - it is as if you are starting from fresh and the only information that you retain is your current level and golds - items that are not stored locally on the device you are playing on. That is why we always try and warn the players that de-installing and re-installing the game should only be done as a last resort.
I am sorry that you lost all those boosters, but you won't be able to get them back. You will just have to start saving them up again.