Java tutorial
//package com.java2s; import java.io.File; import android.content.Context; public class Main { private static final String INSTALLATION = "INSTALLATION"; public static boolean isInstalled(final Context context) { final File installation = getInstallationFile(context); return installation.exists(); } private static File getInstallationFile(final Context context) { return new File(context.getFilesDir(), INSTALLATION); } }