add whisper download utils. add react-navigator.

app/service/download.ts

@@ -0,0 +1,36 @@
+import { useState, useEffect, useRef } from 'react';
+import { Text, View, Button, Platform } from 'react-native';
+import * as Device from 'expo-device';
+import * as Notifications from 'expo-notifications';
+import Constants from 'expo-constants';
+
+
+export function initNotifications() {
+    Notifications.setNotificationHandler({
+        handleNotification: async () => ({
+          shouldShowAlert: true,
+          shouldPlaySound: true,
+          shouldSetBadge: true,
+        }),
+      });
+}
+
+async function sendPushNotification(expoPushToken: string) {
+    const message = {
+      to: expoPushToken,
+      sound: 'default',
+      title: 'Original Title',
+      body: 'And here is the body!',
+      data: { someData: 'goes here' },
+    };
+  
+    await fetch('https://exp.host/--/api/v2/push/send', {
+      method: 'POST',
+      headers: {
+        Accept: 'application/json',
+        'Accept-encoding': 'gzip, deflate',
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify(message),
+    });
+  }