I just want all the beacons of all proximityUUID available in area for IOS. Like in android just by
 entering
 `regions.add(Region(identifier: 'ibeacon'));`

if (_streamRanging != null) {
  if (_streamRanging.isPaused) {
    _streamRanging.resume();
    return;
  }
}

flutterBeacon.monitoring(regions).listen((result) async {
      //get gps coordinates
      Position position = await Geolocator().getCurrentPosition(desiredAccuracy: LocationAccuracy.best);
      if(position == null){
        position = await Geolocator().getLastKnownPosition(desiredAccuracy: LocationAccuracy.best);
      }

      if(result.monitoringEventType == MonitoringEventType.didEnterRegion) {
        //save to store with timestamp
        Storage().storeValue(
            "beacon_last_latitude", position.latitude.toString());
        Storage().storeValue(
            "beacon_last_longitude", position.longitude.toString());
        Storage().storeValue("beacon_last_timestamp",
            new DateTime.now().millisecondsSinceEpoch.toString());

        prefix0.log("BEACON FOUND: " + position.latitude.toString() + " - " +
            position.longitude.toString());
      } else if(result.monitoringEventType == MonitoringEventType.didExitRegion) {
        LocalNotification(BEACON_NOTIFICATION_CHANNEL, "Out of range", "Warning, your luggage is out of range.").send();
      }
});

    _streamRanging = flutterBeacon.ranging(regions).listen((result) {
      if (result != null && mounted) {

        _regionBeacons[result.region] = result.beacons;
        _beacons.clear();
        if (result.beacons.length == 0 && globals.Minor != 0){
          setState(() {
            globals.Minor = 0;
            globals.Ubicado = "Desconocida";
            globals.codArea = '0';
            globals.Sucio = false;
            globals.Limpio = false;
          });
        }
        _regionBeacons.values.forEach((list) {
          _beacons.addAll(list);
          if (_beacons[0].minor != globals.Minor){
            globals.Minor = _beacons[0].minor;
            BuscarArea(globals.Minor);
          }
          _beacons.sort(_compareParameters);
        });
      }
    });

import 'dart:io';

import 'package:flutter/material.dart';
import 'dart:async';

import 'package:flutter/services.dart';
import 'package:flutter_beacon/flutter_beacon.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  StreamSubscription<RangingResult> _streamRanging;
  final _regionBeacons = <Region, List<Beacon>>{};
  final _beacons = <Beacon>[];

  @override
  void initState() {
    super.initState();

    initBeacon();
  }

  initBeacon() async {
    try {
      await flutterBeacon.initializeScanning;
      print('Beacon scanner initialized');
    } on PlatformException catch (e) {
      print(e);
    }

    final regions = <Region>[];

    if (Platform.isIOS) {
      regions.add(Region(
          identifier: 'Apple Airlocate',
          proximityUUID: 'E2C56DB5-DFFB-48D2-B060-D0F5A71096E0'));
    } else {
      // android platform, it can ranging out of beacon that filter all of Proximity UUID
     regions.add(Region(identifier: 'com.beacon'));
    }

    flutterBeacon.monitoring(regions).listen((MonitoringResult result) {
      // result contains a region, event type and event state
    });

    _streamRanging = flutterBeacon.ranging(regions).listen((result) {
      result.beacons.forEach((b) {
        print(b.major);
        _beacons.sort(_compareParameters);
      });
    });
  }

  int _compareParameters(Beacon a, Beacon b) {
    int compare = a.proximityUUID.compareTo(b.proximityUUID);

    if (compare == 0) {
      compare = a.major.compareTo(b.major);
    }
    return compare;
  }

  @override
  void dispose() {
    if (_streamRanging != null) {
      _streamRanging.cancel();
    }
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Test détection balises'),
        ),
        body: _beacons == null
          ? Center(child: CircularProgressIndicator())
            : ListView(
          children: ListTile.divideTiles(
              context: context,
              tiles: _beacons.map((beacon) {
                return ListTile(
                  title: Text(beacon.proximityUUID),
                  subtitle: new Row(
                    mainAxisSize: MainAxisSize.max,
                    children: <Widget>[
                      Flexible(
                          child: Text(
                              'Major: ${beacon.major}\n',
                              style: TextStyle(fontSize: 13.0)),
                          flex: 1,
                          fit: FlexFit.tight),
                      Flexible(
                          child: Text(
                              'Accuracy: ${beacon.accuracy}m\nRSSI: ${beacon.rssi}',
                              style: TextStyle(fontSize: 13.0)),
                          flex: 2,
                          fit: FlexFit.tight)
                    ],
                  ),
                );
              })).toList(),
        ),
      ),
    );
  }
}

I/flutter (11033): Caught error: PlatformException(error, length=0; index=0, null)
I/flutter (11033): #0      StandardMethodCodec.decodeEnvelope 
package:flutter/…/services/message_codecs.dart:569
I/flutter (11033): #1      MethodChannel.invokeMethod 
package:flutter/…/services/platform_channel.dart:321
I/flutter (11033): <asynchronous suspension>
I/flutter (11033): #2      FlutterBeacon.initializeScanning
package:flutter_beacon/flutter_beacon.dart:54
I/flutter (11033): <asynchronous suspension>

import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_beacon/flutter_beacon.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String result;
  StreamSubscription<RangingResult> _streamRanging;
  final regions = <Region>[];

 ** ranging() async {
    try {
      await flutterBeacon.initializeAndCheckScanning;
    } catch (e) {}

    if (Platform.isIOS) {
      regions.add(Region(
          identifier: 'Apple Airlocate',
          proximityUUID: 'E2C56DB5-DFFB-48D2-B060-D0F5A71096E0'));
    } else {
      regions.add(Region(
          identifier: null,
          proximityUUID: '87b7696c-3700-4fb6-b274-d089dfc44686'));
    }

    _streamRanging =
        flutterBeacon.ranging(regions).listen((RangingResult result) {
      print(result.region);
    });
  }**

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        body: Center(
          child: new Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Container(
                width: 100,
                child: MaterialButton(
                  child: Text("Subscribe"),
                  color: Colors.blue,
                 ** onPressed: () {
                    ranging();
                  },**
                ),
              ),
              Container(
                width: 100,
                child: MaterialButton(
                  child: Text("Cancel"),
                  color: Colors.blue,
               **   onPressed: () {
                    _streamRanging.cancel();
                    regions.removeLast();
                    regions.add(Region(
                        identifier: null,
                        proximityUUID: '98173b7d-2444-424a-bed9-7acf4bf97a50'));
                    _streamRanging = flutterBeacon
                        .ranging(regions)
                        .listen((RangingResult result) {
                      print(result.region);
                    });
                  },**
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

double calculateAccuracy(int txPower, double rssi){
    if(rssi == 0)
      return -1.0;
    double ratio = rssi*1.0/txPower;
    if(ratio < 1.0)
      return pow(ratio, 10);
    else {
      double accuracy = (0.89976)*pow(ratio,7.7095) + 0.111;
      return num.parse(accuracy.toStringAsFixed(2));
    }
  }

════════ Exception caught by services library ══════════════════════════════════
The following PlatformException was thrown while activating platform stream on channel flutter_beacon_event:
PlatformException(error, Unable to parse Identifier., null)

When the exception was thrown, this was the stack
#0      StandardMethodCodec.decodeEnvelope 
package:flutter/…/services/message_codecs.dart:569
#1      MethodChannel._invokeMethod 
package:flutter/…/services/platform_channel.dart:156
<asynchronous suspension>
#2      MethodChannel.invokeMethod 
package:flutter/…/services/platform_channel.dart:329
#3      EventChannel.receiveBroadcastStream.<anonymous closure> 
package:flutter/…/services/platform_channel.dart:519
...
════════════════════════════════════════════════════════════════════════════════

  Future<List<Region>> fetchBeacons() async {
    List<Region> regions = [];
    regions = [
      Region(
          proximityUUID: 'AFC0FF69-3ACB-4A99-9F6A-2A4B6F786619',
          identifier: 'T-Shirt Beacon',
          major: 1,
          minor: 1),
      Region(
          proximityUUID: '705DAEE5-56BC-415A-839B-4AE00FC29946',
          identifier: 'Test',
          major: 1,
          minor: 1),
    ];
    return regions;
  }

  Future<Stream<RangingResult>> scanBeacons() async {
    await flutterBeacon.initializeScanning;
    List<Region> regions = await fetchBeacons();
    Stream<RangingResult> beaconStream = flutterBeacon.ranging(regions);
    beaconStream.listen(print);
    return beaconStream;
  }Ï

RangingResult{"region": {"identifier":"T-Shirt Beacon","proximityUUID":"AFC0FF69-3ACB-4A99-9F6A-2A4B6F786619","major":1,"minor":1}, "beacons": []}

flutter: RangingResult{"region": {"identifier":"Test","proximityUUID":"705DAEE5-56BC-415A-839B-4AE00FC29946","major":1,"minor":1}, "beacons": []}
flutter: RangingResult{"region": {"identifier":"T-Shirt Beacon","proximityUUID":"AFC0FF69-3ACB-4A99-9F6A-2A4B6F786619","major":1,"minor":1}, "beacons": []}
flutter: RangingResult{"region": {"identifier":"T-Shirt Beacon","proximityUUID":"AFC0FF69-3ACB-4A99-9F6A-2A4B6F786619","major":1,"minor":1}, "beacons": []}

class _MyHomePageState extends State<MyHomePage> {

 @override
  void initState() {
      super.initState();
     ...
     initializeScanning();
 }

 void initializeScanning() async {
    try {
      await flutterBeacon.initializeAndCheckScanning;
      startRanging();
    } catch(e) {
      print(e);
    }
  }
 
 void startRanging()
 {
   final regions = <Region>[
      Region(identifier: Platform.isIOS ? this.identifier : null, 
                  proximityUUID: this.uuid)
  ];

  _streamRanging = flutterBeacon.ranging(regions).listen((RangingResult result) { 
      //Do some calculations for distance on detected beacon
      //Display the result in ListView
      //Fire local notification
  });
 }

}

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v1.1.8, on Linux, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[✓] Android Studio (version 3.3)
[!] VS Code (version 1.27.2)
    ✗ Flutter extension not installed; install from
      https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter
[✓] Connected device (1 available)

! Doctor found issues in 1 category.

Note: /home/xxx/.pub-cache/hosted/pub.dartlang.org/firebase_messaging-3.0.0/android/src/main/java/io/flutter/plugins/firebasemessaging/FlutterFirebaseInstanceIDService.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
/home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java:14: error: cannot find symbol
import android.support.v4.app.ActivityCompat;
                             ^
  symbol:   class ActivityCompat
  location: package android.support.v4.app
/home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java:15: error: package android.support.v4.content does not exist
import android.support.v4.content.ContextCompat;
                                 ^
/home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java:113: error: cannot find symbol
        ActivityCompat.requestPermissions(registrar.activity(), new String[]{
        ^
  symbol:   variable ActivityCompat
  location: class FlutterBeaconPlugin
/home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java:122: error: cannot find symbol
      return ContextCompat.checkSelfPermission(registrar.activity(),
             ^
  symbol:   variable ContextCompat
  location: class FlutterBeaconPlugin
/home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java:229: error: cannot find symbol
      if (!ActivityCompat.shouldShowRequestPermissionRationale(registrar.activity(), permission)) {
           ^
  symbol:   variable ActivityCompat
  location: class FlutterBeaconPlugin
/home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java:256: error: cannot find symbol
        ActivityCompat.requestPermissions(registrar.activity(), new String[]{
        ^
  symbol:   variable ActivityCompat
  location: class FlutterBeaconPlugin
Note: /home/xxx/.pub-cache/hosted/pub.dartlang.org/flutter_beacon-0.1.1/android/src/main/java/com/flutterbeacon/FlutterBeaconPlugin.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
6 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':flutter_beacon:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 12s
Finished with error: Gradle task assembleDebug failed with exit code 1

android {
    compileSdkVersion 28
    lintOptions {
        disable 'InvalidPackage'
    }
    defaultConfig {
        applicationId "cz.myapp"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

flutter: Listening to bluetooth state
flutter: AppLifecycleState = AppLifecycleState.resumed
flutter: AppLifecycleState = AppLifecycleState.resumed
flutter: BluetoothState = Instance of 'BluetoothState'
[VERBOSE-2:ui_dart_state.cc(157)] Unhandled Exception: type 'int' is not a subtype of type 'bool'
#0      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:321:13)
<asynchronous suspension>
#1      FlutterBeacon.initializeScanning (package:flutter_beacon/flutter_beacon.dart:65:33)
#2      _MyAppState.initScanBeacon (package:flutter_app/beacon.dart:75:25)
#3      _MyAppState.listeningState.<anonymous closure> (package:flutter_app/beacon.dart:47:11)
#4      _rootRunUnary (dart:async/zone.dart:1134:38)
#5      _CustomZone.runUnary (dart:async/zone.dart:1031:19)
#6      _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
#7      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
#8      _BufferingStreamSubscription._add (dart:async/stream_impl.dart:265:7)
#9      _ForwardingStreamSubscription._add (dart:async/stream_pipe.dart:134:11)
#10     _MapStream._handleData (dart:async/stream_pipe.dart:234:10)
#11     _ForwardingStreamSubscription._handleData (dart:async/stream_pipe.dart:166:13)
#12     _rootRunUnary (dart:async/zone.dart:1134:38)
#13     _CustomZone.runUnary (dart:async/zone.dart:1031:19)
#14     _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
#15     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
#16     _DelayedData.perform (dart:async/stream_impl.dart:593:14)
#17     _StreamImplEvents.handleNext (dart:async/stream_impl.dart:709:11)
#18     _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:669:7)
#19     _rootRun (dart:async/zone.dart:1122:38)
#20     _CustomZone.run (dart:async/zone.dart:1023:19)
#21     _CustomZone.runGuarded (dart:async/zone.dart:925:7)
#22     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:965:23)
#23     _rootRun (dart:async/zone.dart:1126:13)
#24     _CustomZone.run (dart:async/zone.dart:1023:19)
#25     _CustomZone.runGuarded (dart:async/zone.dart:925:7)
#26     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:965:23)
#27     _microtaskLoop (dart:async/schedule_microtask.dart:43:21)
#28     _startMicrotaskLoop (dart:async/schedule_microtask.dart:52:5)