Kotlin is an open source, statically-typed programming language officially supported by Google for Android application development whereas Flutter is an open source mobile UI framework by Google. It allows you to create two different applications (for iOS and Android) with a single code base.

When to opt for Kotlin?

The scale of app development using Kotlin is unlimited. Some companies that have used Kotlin in their application is Uber and Pinterest.

Following are the instances where Kotlin overrides any other programming language for applications using mobile technologies.

1. Adding new features to an existing app: Kotlin works smoothly and is compatible with Java and its components. If you wish to add some new features to an existing app, it would be simply better to use Kotlin than going for an entire revamp of the existing architecture. 
2. Simple syntax for complex codes: With an inherent syntax, it easy to code and deploy them using Kotlin. Kotlin is also easy to maintain considering the apps that require heavy coding.  
3. Inherent debugging: Kotlin’s compiler can find bugs easily and prevent them from occurring again. Another benefit of Kotlin can report and resolve crashes easily and is much safer than Java.         

When to opt for Flutter?

Flutter got much attention because apps developed in Flutter works smoothly in both iOS and Android. Moreover, Flutter fully equipped in building full-fledged applications for diverse domains like e-commerce, utility, social and entertainment.    

1. Easy to Grasp and Use: A major plus point of Flutter is that it is simple to learn as well as use. If mobile application development companies in UAE have used Java or Objective-C or React Native, they will say how easy it is to code using Flutter. It is also a very modern framework with less complexity. 
2. Faster compilation: maximum productivity: Flutter has a unique characteristic called Hot-Reload. It enables to bring changes in your code and view the results instantly. Significant modifications require only a short amount of time such as changes in design changes in size of an element etc.
3. Ideal for Small Scale Minimum Viable Products: If you wish to demonstrate your product to investors as early as possible, Flutter is the best choice. This is because
   • It is economically viable to develop a mobile application with Flutter because only one code base is required to create and maintain two mobile apps for both iOS and Android.
   • You won’t even notice the difference between a native app and a Flutter app.
   • Easy availability and personalization of widgets to create efficient UI for end users.

Conclusion

Flutter and Kotlin both are highly efficient and is getting better with every update. To start with it would be better to sharpen back end development skills in Java followed by Kotlin. Subsequently you would be better equipped to get hold of flutter.