React Native is a Javascript framework that allows us to create mobile that will run on both Andriod and iOS.

Expo is a framework and a platform for universal React applications. It is a set of tools and services built around React Native and native platforms that help you develop, build, deploy, and quickly iterate on iOS, Android, and web apps from the same JavaScript/TypeScript codebase.

We need to have a knowledge of javascript and reactjs.

Firstly, things needed.

1. Node.js install
2. Code Editor (Vs code)
3. React Native Tools Extension

Step 1

npm install -g expo-cli

Step 2
Create a new expo project, let's call it firstProject

expo init AwesomeProject
cd AwesomeProject

Step 3

Run npm start

Step 4

Download expo on your playstore on you phone and install. Also after expo app have been launch you'll see a barcode, scan the barcode with your phone camera.