There are a number of different ways that you can use an open source food delivery app. Firstly, you will need to download the app onto your phone. This is the easiest way to get started and it's also free. You will then have access to the hundreds of restaurants in your area that offer food delivery services. You can search for a restaurant by its name or type, or by using the map feature on the app. Once you have found a restaurant that you would like to order from, all you need to do is tap on it and then tap again on "Order Food."

You will then be able to view all of the available menu items and make your selection before confirming your order with a few taps of your finger. If there are any special instructions for when your food should arrive or a special request, this will be explained on the order confirmation screen. Once confirmation is completed, you will then get a receipt that is already pre-filled with your order details. You can also view your recent orders on the app as well as adjust changes in orders before they are delivered to your door.