ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(context);
locationProvider.getLastKnownLocation()
    .subscribe(new Action1<Location>() {
        @Override
        public void call(Location location) {
            doSthImportantWithObtainedLocation(location);
        }
    });

LocationRequest request = LocationRequest.create() //standard GMS LocationRequest
                                  .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                                  .setNumUpdates(5)
                                  .setInterval(100);

ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(context);
Subscription subscription = locationUpdatesObservable = locationProvider.getUpdatedLocation(request)
    .filter(...)    // you can filter location updates
    .map(...)       // you can map location to sth different
    .flatMap(...)   // or event flat map
    ...             // and do everything else that is provided by RxJava
    .subscribe(new Action1<Location>() {
        @Override
        public void call(Location location) {
            doSthImportantWithObtainedLocation(location);
        }
    });

subscription.unsubscribe();

Observable<List<Address> geocodeObservable = locationProvider
    .getGeocodeObservable(location.getLatitude(), location.getLongitude(), MAX_ADDRESSES);

geocodeObservable
    .subscribeOn(Schedulers.io())               // use I/O thread to query for addresses
    .observeOn(AndroidSchedulers.mainThread())  // return result in main android thread to manipulate UI
    .subscribe(...);

LocationRequest req = LocationRequest.create()
                         .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                         .setExpirationDuration(TimeUnit.SECONDS.toMillis(LOCATION_TIMEOUT_IN_SECONDS)
                         .setInterval(LOCATION_UPDATE_INTERVAL);

Observable<Location> goodEnoughQuicklyOrNothingObservable = locationProvider.getUpdatedLocation(req)
            .filter(new Func1<Location, Boolean>() {
                @Override
                public Boolean call(Location location) {
                    return location.getAccuracy() < SUFFICIENT_ACCURACY;
                }
            })
            .timeout(LOCATION_TIMEOUT_IN_SECONDS, TimeUnit.SECONDS, Observable.from((Location) null), AndroidSchedulers.mainThread())
            .first()
            .observeOn(AndroidSchedulers.mainThread());

goodEnoughQuicklyOrNothingObservable.subscribe(...);