The order board allows you to trade items you produce for coins and experience points.

 

To start trading, tap the board and then select an order from the map. To the right of the map, you will see a list of items required to fulfill the order. Tap the Send button under the list to complete the trade.

 

You can also skip an order by tapping this button:

 

Completing multiple orders will reward you with a chest containing energy, coins, and growth elixirs. Your progress towards the next chest is represented by the bar at the bottom of the map. The third and fourth chests on the bar also contain diamonds and sets of tools.

 

Sometimes you will get special orders with a shiny icon. These orders require more items to complete, but also give you greater rewards, including sets of tools.

 

Hint: sets of tools are required to upgrade your storage.