1. Programming languages: A application developer should have a good understanding of programming languages such as Java and Kotlin for Android development and Swift and Objective-C for iOS development.
2. Cross-platform development: A developer should have experience working with cross-platform app development tools such as React Native, Flutter, or Xamarin to develop apps for both Android and iOS platforms.
3. Development frameworks and tools: A application developer should have a good understanding of popular app development frameworks such as Android SDK and iOS SDK, as well as popular app development tools such as Android Studio, Xcode, and Visual Studio.
4. User interface design: A application developer should have experience in designing user interfaces that are user-friendly and visually appealing, using tools such as Sketch, Adobe XD, or Figma.
5. API integration: A developer should have experience in integrating APIs into applications to access data from external sources.
6. Testing and debugging: A developer should have experience in testing and debugging applications using popular tools such as Android Debug Bridge (ADB) and Xcode Instruments.
7. Version control: A developer should have experience using version control systems such as Git to manage code changes and collaborate with other developers.
8. Knowledge of app architecture patterns: A developer should have experience with app architecture patterns such as Model-View-Controller (MVC), Model-View-ViewModel (MVVM), or Clean Architecture to develop scalable and maintainable apps.
9. Communication and collaboration: A developer should have good communication skills and be able to collaborate effectively with other team members, such as designers and project managers.