
iOS CallKit framework and Android ConnectionService for React Native
React Native CallKeep is a library that utilizes the iOS 10 framework CallKit and Android ConnectionService, simplifying the development process for VoIP applications built using React Native. It enables better integration and functionality with these native systems.
React Native CallKeep simplifies the development process for VoIP applications by integrating with CallKit on iOS and ConnectionService on Android. It offers features such as customization of SystemUI display, support for different call types, and video calling capabilities. However, it is important to note that this library is only compatible with real devices and not simulators.

React Native is a framework for building mobile applications using React and JavaScript. It enables developers to write once and deploy to multiple platforms, including iOS, Android, and the web, while providing a native app-like experience to users.