public static int getUniqueNotificationId() {
        final int id = getInt(R.string.pref_next_unique_notification_id, Notifications.UNIQUE_ID_RANGE_START);
        putInt(R.string.pref_next_unique_notification_id, id + 1);
        return id;
    }
checks whether legacy folder needs to be migrated
(legacy value is set and not yet migrated)
(used by the installation / migration wizard)
main/src/main/java/cgeo/geocaching/settings/Settings.java