The App.js file I used for the react-navigation pull request #2695

App.js

import React, { Component } from 'react';
import {
  Platform,
  StyleSheet,
  Text,
  View,
  Button
} from 'react-native';
import { StackNavigator, TabNavigator } from 'react-navigation';
import Dimensions from 'Dimensions'
var {height, width} = Dimensions.get('window')

const viewStyle = {height, width, alignItems: 'center', justifyContent: 'center'}

class Tab1Screen extends React.Component {
  static navigationOptions = {
    title: 'Tab 1 Screen',
  };
  render() {
    return (
      <View style={viewStyle}>
        <Text>Tab 1 Screen</Text>
      </View>
    );
  }
}

class Tab2Screen1 extends React.Component {
  static navigationOptions = {
    title: 'Tab 2 Screen 1',
  };
  render() {
    const { navigate, state } = this.props.navigation;
    const { params } = state
    return (
      <View style={viewStyle}>
        <Text>Tab 2 Nested Screen 1</Text>
        <Text>Params: {JSON.stringify(params, null, 2)}</Text>
        <Button
          onPress={() => navigate('Nested2', {exampleKey: 'exampleValue'})}
          title="Go to Screen 2"
        />
      </View>
    );
  }
}

class Tab2Screen2 extends React.Component {
  static navigationOptions = {
    title: 'Tab 2 Screen 2',
  };
  render() {
    const { navigate, state } = this.props.navigation;
    const { params } = state
    return (
      <View style={viewStyle}>
        <Text>Tab 2 Nested Screen 2</Text>
        <Text>Params: {JSON.stringify(params, null, 2)}</Text>
      </View>
    );
  }
}

const Tab2Screen = StackNavigator({
  Nested1: {screen: Tab2Screen1, path: ':id1'},
  Nested2: {screen: Tab2Screen2, path: ':id1/:id2'}
})

const TheTabs = TabNavigator({
  Tab1: {screen: Tab1Screen, path: 'tab-1'},
  Tab2: {screen: Tab2Screen, path: 'tab-2'}
});

class HomeScreen extends React.Component {
  render() {
    const { navigate} = this.props.navigation;
    return (
      <View style={viewStyle}>
        <Text>Home Screen</Text>
        <Button
          onPress={() => navigate('TheTabs', {exampleKey: 'exampleValue'})}
          title="Go to TheTabs"
        />
      </View>
    );
  }
}

const SimpleApp = StackNavigator({
  Home: {screen: HomeScreen, path: 'home'},
  TheTabs: {screen: TheTabs, path: 'tabs'}
}, {
  mode: 'modal',
  headerMode: 'none'
});

const prefix = Platform.OS == 'android' ? 'mychat://mychat/' : 'mychat://';
const MainApp = () => <SimpleApp uriPrefix={prefix} />;

export default MainApp