Onetime Purchase feature in our food delivery app Delivery App

I'm looking to develop a mobile app similar to Country Delight. The app should have:

- One-time purchase options: Aside from subscriptions, users should also have the ability to make one-time purchases.
- User account management: The app should have a robust user account management system, allowing users to create, modify and manage their accounts.
- Push notifications: The app should support push notifications for order updates, subscription renewals, and promotional offers.
- Delivery partners should be able to login and view the customer's location on map

The app needs to support both iOS and Android platforms. A key requirement is the integration of PhonePay as the primary payment gateway. Ideal candidates for this project should have:

- Proven experience in building e-commerce or subscription-based mobile apps.
- Strong understanding of user account management systems.
- Expertise in integrating different payment gateways, particularly PhonePay.
- Extensive experience in cross-platform (iOS and Android) app development.