HOW TO PURCHASE OR SELL BOOSTERS?
You can find all your boosters, and gems in your Inventory.
Read more about the boosters:
In the inventory you can purchase 1 or 10 boosters with the green + button.
If you'd like to sell your redundant boosters you can do that with the red - button. (You can sell 1 or 10 boosters at a time.)
IMPORTANT NOTE: You can not sell your Season Point Saver Boosters.
GEMS:
In the inventory you can find your GEMS too.
To know more about the GEMS read our article about how to get them.