React Native is a framework for building native iOS and Android apps. It was developed by Facebook and immediately gained popularity. Today along with proprietary solutions provided by the two major mobile platforms React Native stands tall as a preferred app development framework. Parts of facebooks own app, Instagram and other apps like Page Manager and Ads manager are entirely build up using the React Native framework.
Companies like Tesla, Bloomberg, Pinterest and Uber have also started using React Native as a platform of choice for building their applications.
You can read more about React Native here.
You can hire a React Native developer to boost your app development process and get both your iOS and Android apps developed in the price of one.