Address tracking and notification sounds.

frontend/src/app/services/audio.service.ts

@@ -0,0 +1,21 @@
+import { Injectable } from '@angular/core';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class AudioService {
+  audio = new Audio();
+
+  constructor() { }
+
+  public playSound(name: 'magic' | 'chime' | 'cha-ching') {
+    try {
+      this.audio.src = '../../../assets/sounds/' + name + '.mp3';
+      this.audio.load();
+      this.audio.play();
+    } catch (e) {
+      console.log('Play sound failed', e);
+    }
+  }
+
+}