In Short:

You will learn how to add Google Analytics without cordova plugin and track page transitions and your own events

Pre-Condition:

You have created a Google Analytics account and also have registered a website based project for your ionic app. Also you have extracted your Tracker Id from your GA code tracking snippet.

The Tracker format has the following syntax:

'XX-XXXXXXXX-X'

How it works

Step 1
Install the following dependencies

npm install --save @types/google.analytics

Step 2
Add the following snippet to your index.html

<script>
  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
  })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
</script>

Step 3
Create a new Provider for handling the Google Analytics interactions and import it to your app.module.ts file

import { AnalyticsService } from './analytics.service';
...
@NgModule({
 ...
  providers: [
    ...
    AnalyticsService,
    ...
  ]
})
import { Injectable } from '@angular/core';
declare var ga;

@Injectable({
  providedIn: 'root'
})
export class AnalyticsService {

  constructor() { }

  setTracker(tracker) {
    if ( !localStorage.getItem('ga:clientId') ) {
      localStorage.setItem( 'ga:clientId', tracker.get('clientId') );
    }
  }

  startTrackerWithId(id) {
    ga('create', {
      storage: 'none',    ​
      trackingId: id,
      clientId: localStorage.getItem('ga:clientId')
    });    ​
    ga('set', 'checkProtocolTask', null);​
    ga('set', 'transportUrl', 'https://www.google-analytics.com/collect');
    ga(this.setTracker);
  }

  trackView(pageUrl: string, screenName: string) {
    ga('set', {
      page: pageUrl,
      title: screenName
    });
    ga('send', 'pageview');
  }

  trackEvent(category, action, label?, value?) {
    ga('send', 'event', {
      eventCategory: category,
      eventLabel: label,
      eventAction: action,
      eventValue: value
    });
  }
}

Step 4
Init your app with your Google Analytics tracker id in the app.component.ts

Also you can register on the Angular router events and track switches between pages automatically

...
import { AnalyticsService } from './analytics.service';
import { Router, NavigationStart } from '@angular/router';
import { Title } from '@angular/platform-browser';

@Component({
  selector: 'app-root',
  templateUrl: 'app.component.html'
})
export class AppComponent {
  constructor(
    ...
    private analyticsService: AnalyticsService,
    public router: Router,
    private title: Title,
  ) {
    this.initializeApp();
  }

  initializeApp() {
    //Start track passing Tracker Id
    this.analyticsService.startTrackerWithId('XX-XXXXXXXX-X');
    ...
    this.router.events
    .subscribe(event => {
      //observe router and when it start navigation it will track the view
      if (event instanceof NavigationStart) {
        let title = this.title.getTitle();
        //get title if it was sent on state
        if (this.router.getCurrentNavigation().extras.state) {
          title = this.router.getCurrentNavigation().extras.state.title;
        }
        //pass url and page title 
        this.analyticsService.trackView(event.url, title);
      }
    });
  }
}

Step 5
For creating specific events. Add the following code to your services:

import { AnalyticsService } from './analytics.service';

export class MyServicePage {	
  constructor(
    public analytics: AnalyticsService,
  ) {}
  
  playSoundExample() {
    this.analytics.trackEvent('User Interaction', 'Play Sound', 'Super Mario Sound');
  }
}

Step 6 (Optional)
Also you can add specific title descriptions for page transitions

<a routerLink="/items/123" [state]="{ title: 'Test Link' }" routerDirection="root">
  My test link
</a>