AdFree is an Android app that alters your hosts file to make most ad banners not renderable (by altering the ad networks IP addresses to local IP). It's nice but developers who develop apps for free and putting ad banners in the apps in the hope of making some pocket money, so that they can continue supporting and enhancing the app. AdFree destroys that last little hope. And I don't like that.

AdFree Detector detects whether the Android phone has AdFree package installed, as well as finding out if your ad network IP has been altered (and thus no ads will be shown to the user).

It's a simple JAR lib that you can include in your Android apps.

Have fun :)