One major factor that makes all the difference in a clone app is inevitably the features integrated into it. Some of the unique features of an Instacart clone app include,

In-app wallet: Users can pay for their orders seamlessly without entering their account details every time.
Multi-lingual support: Users can access the app in the language of their preference, thereby enhancing their convenience.
Real-time tracking: Users get to track delivery agents in real-time with this feature.
Inventory management: Grocery store owners get to add or remove products seamlessly based on their availability.

All these factors add to the popularity of the Instacart clone app.