Hi! I want to share my earning method. I have a couple of sites where I publish free Android Apps and Games. The profit from ads is fine, but there is no profit from application installs.
I add Ads SDK to APK files that I share. SDK is an advertising code and when users download and install these apps they see ads (my profit!).

How to add Ads SDK to APK files:
Register on affilight site and add your APKs to the converter. Upload "ready" apk with Ads back to your site. And you are done!
I want recommend you use most popular games to get max profit. One install = up to 10 cents.