Hi everyone! I hope you’re all having a wonderful day.
Just passing by and would like to suggest that you check OfferDaddy if you have new or already running app that you need to monetize.
I heard they have Android SDKs which natively integrate their offer walls / ads / surveys and allow you and your users to gain money! 
I hope this helps you, and let me know if it does! :*
Hey
Making Money From Android App Monetization Technique Involves Showing Ads To Users Of The App.
Unlock Hidden Monetization Levels With Alphagravel Ads.
Mobile Advertising SDK is the easiest way to monetize mobile ads. This concept offer you Android app for free and display adverts in the app to generate revenue. When a user clicks on the ad you will earn money. You can say its another very useful android income method.