Initial Setup (React Native)

index.js

/**
 * @format
 */

import React from 'react';
import {AppRegistry, Text, TextInput} from 'react-native';
import App from './App';
import {name as appName} from './app.json';

// This is done to ensure that the text size remains consistent across all devices.
if (Text.defaultProps) {
  Text.defaultProps.allowFontScaling = false;
} else {
  Text.defaultProps = {};
  Text.defaultProps.allowFontScaling = false;
}
if (TextInput.defaultProps) {
  TextInput.defaultProps.allowFontScaling = false;
} else {
  TextInput.defaultProps = {};
  TextInput.defaultProps.allowFontScaling = false;
}

// Check if app was launched in the background and conditionally render null if so
function HeadlessCheck({isHeadless}) {
  if (isHeadless) {
    // App has been launched in the background by iOS, ignore
    return null;
  }

  // Render the app component on foreground launch
  return <App />;
}

AppRegistry.registerComponent(appName, () => HeadlessCheck);