PWA in Ionic 4 now is too much easy than never! you can start a new Ionic 4 app with (Angular by default) following the steps suggested by the Ionicframework beta documents:
https://ionictheme.com/create-a-pwa-in-ionic4-using-angular/
A comprehensive step by step tutorial on how to create Local Notification using Ionic 3, Angular 5 and Cordova with Native Local Notification Plugin. The story for this tutorial is just creating multiple notifications that input by the user inside the app. So, inside the app just a form for input the notification description and time. The rest of notification function will be handled by the system.
260+ Ionic Framework Resources
http://mcgivery.com/100-ionic-framework-resources/
There are many posts and articles on the Ionic Framework but sometimes it is difficult to locate exactly what you need. This list is a an attempt to create a comprehensive list of tutorials that cover as many topics as possible. I will update this list as I discover new posts and as new posts are suggested.
Quick Start with Ionic + Firebase https://ionictheme.com/quick-start-with-ionic-firebase/
Before you can start building an application using Ionic, you need to get everything setup on your computer first. If you have already installed Node.js along with Ionic and Cordova, you may skip this step.
How To Debug White Screen Ionic error on devices https://medium.com/@jomendezdev/how-to-debug-white-screen-ionic-error-on-devices-2a081d536ba7