1. Flutter

Flutter, created by Google, has surged in popularity for cross-platform app development. It enables developers to build natively compiled applications for mobile, web, and desktop from a unified codebase. 

Key Features:

• Hot Reload: Allows immediate visibility of changes without needing to restart the app.
• Rich Widgets: Provides customizable widgets for constructing native interfaces.
• Single Codebase: Facilitates development for various platforms at once. 
• Ideal For: Startups and companies looking for swift development across multiple platforms. ​ 

2. React Native

React Native, overseen by Facebook, allows for the creation of mobile applications using JavaScript and React. It is recognized for producing near-native performance. ​ 

Key Features:

• Reusable Components: Simplifies development and upkeep.
• Large Community: Offers extensive libraries and support.
• Cross-Platform: Enables development for both iOS and Android with shared code. ​ 
• Ideal For: Projects that need quick deployment and a native appearance. ​

3. Xamarin  

Xamarin, developed by Microsoft, enables developers to create native applications using C#. Its integration with the .NET ecosystem makes it an excellent choice for applications at the enterprise level.  

Key Features:  

• Code Reusability: Achieve up to 90% code sharing across different platforms.  
• Performance: Delivers performance close to that of native apps.  
• Integration: Offers seamless compatibility with Microsoft tools and services.  
• Ideal For: Organizations already utilizing Microsoft technologies.  

4. Ionic  

Ionic is an open-source framework designed for the creation of hybrid mobile applications using web technologies such as HTML, CSS, and JavaScript.  

Key Features:  

• Cross-Platform Compatibility: Create applications for various platforms using a single codebase.  
• UI Components: Includes pre-built components for faster development.  
• Integration: Works effectively with Angular, React, and Vue.  
• Ideal For: Developers with experience in web development looking to create mobile applications.