react-native.md

react-native init APPNAME
cd APPNAME/
npm i --save react-native-crypto
npm i --save react-native-randombytes
npm i --save-dev rn-nodeify@latest
./node_modules/.bin/rn-nodeify --install
npm i --save node-libs-browser
npm i base-64

modify APPNAME/metro.config.js to read:

const extraNodeModules = require('node-libs-browser');

module.exports = {
	resolver: {
		extraNodeModules,
	},
	transformer: {
		getTransformOptions: async () => ({
			transform: {
				experimentalImportSupport: false,
				inlineRequires: false,
			},
		}),
	},
};

modify shim.js to read:

import { decode, encode } from 'base-64';

if (!global.btoa) global.btoa = encode;
if (!global.atob) global.atob = decode;

if (typeof __dirname === 'undefined') global.__dirname = '/';
if (typeof __filename === 'undefined') global.__filename = '';
if (typeof process === 'undefined') {
	global.process = require('process');
} else {
	const bProcess = require('process');
	for (var p in bProcess) {
		if (!(p in process)) {
			process[p] = bProcess[p];
		}
	}
}

process.browser = false;
if (typeof Buffer === 'undefined') global.Buffer = require('buffer').Buffer;

if (typeof location === 'undefined')
	global.location = { port: 80, protocol: 'https:' };
const isDev = typeof __DEV__ === 'boolean' && __DEV__;
process.env['NODE_ENV'] = isDev ? 'development' : 'production';
if (typeof localStorage !== 'undefined') {
	localStorage.debug = isDev ? '*' : '';
}

// If using the crypto shim, uncomment the following line to ensure
// crypto is loaded first, so it can populate global.crypto
require('crypto');

import './shim'; //in the first line of App.js or index.js

npm i -d web3