The first thing that you are going to need would be a foundation to build your food ordering app on. You can just use an uber eats clone app for that. An ubereats clone script will have all the features of popular food delivery apps, and all you have to do is customize it according to your business. This would be better than creating an app from scratch.
You can include these features.
- Delivery Tracking.
- Restaurant KYC.
- Support for restaurant-specific delivery boys. Like restaurants can choose to use their own delivery boys.
- Rewards system for customers.
- Mobile wallet payment options.
- Real-time restaurant status.
These are some of the things that I can think about. Ubereats clone apps will usually have most of these already built-in. The company you hire will also help you get it listed on the mobile app stores like the Apple Store and Google Playstore.
I believe that they will also charge you for the customization process, mostly on an hourly basis. But you should be able to launch a working platform fairly quickly. Hope this helps.