When building a hybrid mobile application the two main things to solve are how to achieve native like performance and portability across different mobile platforms. Fortunately, with React Native we are capable to achieve both performance and great portability. With React Native, you don't build a “mobile web app”, an “HTML5 app”, or a “hybrid app”. You build a real mobile app that's indistinguishable from an app built using Swift/Objective-C or Java. React Native uses the same fundamental UI building blocks as regular iOS and Android apps. You just put those building blocks together using JavaScript and React.

React Native lets you build mobile apps using only JavaScript. It uses the same design as React, letting you compose a rich mobile UI from declarative components.
Tools
Source Control: Git - Github/Bitbucket
ES6/7 Translators: Babel
Builders/Bundlers: Webpack
Unit and Integration Testing
Unit Testing: Jest, Ava, Mocha & Wallaby.js for TDD
E2E Testing: Detox(by Wix)