An instant messaging app like WhatsApp could be created but it is not a walk in the park. It requires much effort and the best approach to develop a solid messaging tool that can swim with the big fish in the industry. Here are some steps that will aid in making a start.

1. Define Your Unique Value Proposition (UVP)

Study the Market: Look at other messaging apps such as WhatsApp, Telegram, and Signal. This way, you will know what has made them attain their success and where there might be some gaps for improvement.

Identify Features: Think about what extra characteristics your WhatsApp clone app would have. For example, while most are known for end-to-end encryption, disappearing messages multimedia sharing, or voice/video calls; uniqueness can be imparted on some added functionalities.

2. Choose the Right Technology Stack

Choose the right and advanced technologies for your instant chat app like WhatsApp. This is the most important factor in your app's user experience and design. 

Most importantly focus on the front end, back end, and real-time location trackers such as Google Maps, Google Play Store, etc. 

3. Design the User Interface (UI)

User-Centered Design: Build a simple and intuitive interface. It should be user-friendly with swift access to chats, contacts, and settings.

Consistency: Keep a consistent design across all platforms for a seamless user experience.

Testing: Refine UI according to user feedback through user testing.

4. Develop Core Features

User Authentication: Provide for secure user registration and login using phone numbers or email. Incorporate two-factor authentication (2FA) for more security.

Chat Functionality: Create one-to-one messaging as well as group chat features. Ensure that multimedia sharing is done smoothly, including images, videos, and voice messages.

Push Notifications: Add push notifications that will notify users in real time when there is a message alert.

End-to-end Encryption: Affect end-to-end encryption of messages sent by users. Use Signal Protocol among other measures to achieve this level of secrecy.

5. Implement Advanced Features

Voice & Video Calls: Enable high-quality voice and video calls using WebRTC.

Status Updates: Allow users to post status updates that disappear after 24 hours, similar to WhatsApp Stories.

Customizable Settings: Provide options for users to customize their privacy settings, notification preferences, and more.

6. Ensure Scalability and Performance

Load Balancing: Use load balancers to distribute traffic evenly and prevent server overload.

Caching: Implement caching mechanisms like Redis to reduce server load and improve performance.

Scalability: Use cloud services like AWS or Google Cloud to scale your WhatsApp clone app as user demand grows.

7. Testing and Debugging

Beta Testing: Conduct beta testing with a limited number of users to identify and correct errors.

Performance Testing: Under different conditions, the app should be tested to guarantee that it can manage heavy traffic and a large number of users.

Security Testing: Carry out regular security audits for identifying as well as solving security threats.

8. Deployment and Maintenance

App Store Submission: Prepare an application for submission into Google Play and Apple App Store following their instructions closely so as not to get rejected.

Continuous Updates: Periodic upgrading of the application adds features, and enhances security while fixing bugs.

Customer Support: To address user problems such as complaints, it is important to offer a strong customer support system.

9. Monetization Strategies

In-App Purchases: Introduce premium features that customers unlock through in-app purchases.

Advertisements: Incorporate unobtrusive advertisements to earn revenue without interrupting the user experience.

Subscription Model: Think about a subscription model for unique functionalities or an ad-free experience.

10. Marketing and Expansion

Launch Campaign: Set up a marketing campaign during your app’s launch using social media platforms, partnerships with influencers, and tailored adverts.

User Retention: Retain users by giving them rewards for referrals, frequent updates, and interesting features as well.

Analytics: Employ analytics tools to track how people use your application up to help you make improvements based on this data understanding.

Conclusion

Building an instant messaging app like WhatsApp requires careful planning, the right technology stack, and a focus on user experience. 

By following these steps, you can create a competitive and successful messaging platform that meets the needs of modern users.