PiracyChecker
An Android library that prevents your app from being pirated
...The real objective here is to raise the bar out of reach of opportunist and automatic attackers. Google Play offers a licensing service that lets you enforce licensing policies for applications that you publish on Google Play. With Google Play Licensing, your application can query Google Play to obtain the licensing status for the current user. Any application that you publish through Google Play can use the Google Play Licensing service. ...