Who installed me ?

The only purpose of this app is to verify how an application behaves if it is installed by Android Market.

The code that is printed in this application is:

String myInstaller = this.getPackageManager().getInstallerPackageName(this.getPackageName());

Don't even bother downloading it if you are not a programmer. Else, try to download the APK yourself and install it thought adb to check the different result.