public static void addCacheToHistory(@NonNull final String geocode) {
        final List<String> history = new ArrayList<>(getLastOpenedCaches());
        // bring entry to front, if it already existed
        history.remove(geocode);
        history.add(0, geocode);
        putStringList(R.string.pref_caches_history, history);
    }
Remember the stata of the "hide visited waypoints"-checkbox in the waypoints overview dialog
main/src/main/java/cgeo/geocaching/settings/Settings.java