The problem Foodie solves

No need for a centralized agent.
Food Orderer, Deliverer and Restaurant all get more benefits than the previous system.
A user can add a restaurant to the Dapp, fill in the menu and prices. An initial fund as eth will be locked from the owner's account.
When an orderer places an order, 100% of the order amount plus delivery charge will be locked from the orderer account.
Next, the restaurant approves the order and starts processing food. A commission percentage on the order amount will be locked from initial funds given by restaurant.
Next, the system looks for a deliverer.
When a deliverer accepts the order, 150% of the order amount is locked from his account.
When deliverer receives food from restaurant, he approves food receival. At this step, restaurant gets paid the amount of order.
When the orderer receives the ordered food, he approves food receival, the deliverer receives the original 150% of the amount, plus the delivery charge plus the restaurant commission.
IF the restaurant fails to deliver after approving, the deliverer and orderer receives the restaurant commission and their original investments.
IF the deliverer fails to deliver after receiving food, the orderer receives his 100% plus 50% from deliverer as reimbursement and restaurant commission is returned to the restaurant.

Challenges we ran into

The main challenge was to design the smart contract for our app, as we have to maintain a lot of issues. We also got stucked calling the methods of the smart contract.