The key features of a food delivery app like Uber Eats include easy login, customizable profiles, location-based services, in-app payments, notifications, and ratings and reviews. For restaurants, features like detailed menu descriptions and order management are essential. For customers, search and filter options and a seamless order placement process are crucial. Couriers need features for order management and status updates. Additionally, the platform administrator handles tasks like relationship management, cancellation management, promotions, advertising, and customer support.