public static boolean checkOfficialDownload(Context context) {

        String installsource = context.getPackageManager().getInstallerPackageName(context.getPackageName());
        try {
            if (installsource.equals("com.google.android.feedback")
                    || installsource.equals("com.android.vending")
                    || installsource.equals("com.amazon.venezia")) {
                return true;
            } else {
                return false;
            }
        } catch (Exception e) {
            return false;
        }
    }