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.
First Version