Ok, it's been three weeks now since looking for a solution on monetizing my app created from C2. Because of being outdated, all the tutorials, plugin and services right now to export and monetize your android app are useless. I don't want to get into details but you know what I mean.
Just to share what I think could be the ultimate solution to exporting your game and monetizing it, is by using Android Studio. Why, you may ask, it may be bulky to download and install, But the benefit is, you'll have your very own apk builder on your computer, never again rely on free crappy sevices online like cocoon, phonegap builder and intel xdk.
How I came up with this idea? Because of looking for a solution I turned to youtube and accidentally stumbled upon some tutorials on how to implement admob ads in Android Studio. So I googled if there's a way to get C2 exported game to Android Studio. Luckily, I found this site, and yeah I followed the instruction and it work. I'm now able to build apks effortlessly.
http://www.mobilezdeveloper.com/running-construct-2-games-on-android-devices-with-cordova-and-android-studio/
Now, the only left thing to solve is what code to edit on the Android Studio files to integrate admob in your project app to show ads. Hopefully someone here in the blog is able to know how to make this work and share a tutorial. I'm pretty sure so many C2 users will benefit from this information.