The Fan Club is an optional, paid feature that unlocks extra level rewards for your favorite Superstars. Each one has a separate pass and the rewards range from in-game currency such as coins and bonus xp to aesthetic items like tints, outfits, weapons skins, avatars and emotes.
The Fan Club passes and levels can be purchased with gems bought in the store.
You can check each individual fan club pass when you open the superstar screen and then tap on the left side. It will open a progress screen showing all the levels and rewards for that Superstar.
If you buy the Fan Club pass when you already have some levels for that Superstar, the pass will unlock previous level rewards and award some xp towards your next level.
Once you get to the last level, you will receive a prestige pass with allows to keep earning levels for your superstar, though no more rewards will be available.
Please note: Aesthetic items are aesthetic only, they do not give any extra perks to your superstar.