public static void toggleService(final ComponentActivity activity, final Geopoint dstCoords) {
        if (isRunning()) {
            stopService(activity);
        } else {
            startService(activity, dstCoords);
            activity.getLifecycle().addObserver(new DefaultLifecycleObserver() {
                @Override
                public void onDestroy(@NonNull final LifecycleOwner owner) {
                    stopService(activity);
                }
            });
        }
    }
Return distance required to be moved based on overall distance.<br>

@param distance in km
@return delta in km
main/src/main/java/cgeo/geocaching/speech/SpeechService.java