Now we have Ionic 4 beta version, which is updated and featured with latest stable Angular 6 version. Angular 6 is having many updates including the new version of Angular Material, CLI tool updates, support for building new libraries etc.
In Ionic 4 also we will have many new changes like the new component, navigation, lazy loading etc, you can read more about Ionic 4 updates on the official blog here.
So here will only discuss Google AdMob most beloved monetization options available for mobile app developers. Google AdMob provides a good source to earn from a free application and it is also very easy to implement in your new or existing Ionic application.