diff --git a/android/src/main/java/com/pauldemarco/flutterblue/FlutterBluePlugin.java b/android/src/main/java/com/pauldemarco/flutterblue/FlutterBluePlugin.java
index de7105c6..4e97c12d 100644
--- a/android/src/main/java/com/pauldemarco/flutterblue/FlutterBluePlugin.java
+++ b/android/src/main/java/com/pauldemarco/flutterblue/FlutterBluePlugin.java
@@ -91,7 +91,7 @@ public static void registerWith(Registrar registrar) {
         this.servicesDiscoveredChannel = new EventChannel(registrar.messenger(), NAMESPACE+"/servicesDiscovered");
         this.characteristicReadChannel = new EventChannel(registrar.messenger(), NAMESPACE+"/characteristicRead");
         this.descriptorReadChannel = new EventChannel(registrar.messenger(), NAMESPACE+"/descriptorRead");
-        this.mBluetoothManager = (BluetoothManager) r.activity().getSystemService(Context.BLUETOOTH_SERVICE);
+        this.mBluetoothManager = (BluetoothManager) r.context().getSystemService(Context.BLUETOOTH_SERVICE);
         this.mBluetoothAdapter = mBluetoothManager.getAdapter();
         channel.setMethodCallHandler(this);
         stateChannel.setStreamHandler(stateHandler);
@@ -116,7 +116,13 @@ public void onMethodCall(MethodCall call, Result result) {
                 result.success(null);
                 break;
             }
-
+            
+            case "setUniqueId":
+            {
+                result.success(null);
+                break;
+            }
+            
             case "state":
             {
                 Protos.BluetoothState.Builder p = Protos.BluetoothState.newBuilder();
@@ -159,8 +165,14 @@ public void onMethodCall(MethodCall call, Result result) {
 
             case "startScan":
             {
-                if (ContextCompat.checkSelfPermission(registrar.activity(), Manifest.permission.ACCESS_COARSE_LOCATION)
-                        != PackageManager.PERMISSION_GRANTED) {
+                boolean hasPermssions = (ContextCompat.checkSelfPermission(registrar.context(), Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED);          
+
+                if (registrar.activity() == null && !hasPermssions) {
+                    result.error("scan_error","bluetooth is not enabled",hasPermssions);
+                    break;
+                }
+
+                if (!hasPermssions) {
                     ActivityCompat.requestPermissions(
                             registrar.activity(),
                             new String[] {
@@ -579,13 +591,13 @@ public void onReceive(Context context, Intent intent) {
         public void onListen(Object o, EventChannel.EventSink eventSink) {
             sink = eventSink;
             IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
-            registrar.activity().registerReceiver(mReceiver, filter);
+            registrar.context().registerReceiver(mReceiver, filter);
         }
 
         @Override
         public void onCancel(Object o) {
             sink = null;
-            registrar.activity().unregisterReceiver(mReceiver);
+            registrar.context().unregisterReceiver(mReceiver);
         }
     };
 
diff --git a/ios/Classes/FlutterBluePlugin.m b/ios/Classes/FlutterBluePlugin.m
index 891e2ec4..564d0aa7 100644
--- a/ios/Classes/FlutterBluePlugin.m
+++ b/ios/Classes/FlutterBluePlugin.m
@@ -42,6 +42,7 @@ @interface FlutterBluePlugin ()
 @property(nonatomic) NSMutableArray *servicesThatNeedDiscovered;
 @property(nonatomic) NSMutableArray *characteristicsThatNeedDiscovered;
 @property(nonatomic) LogLevel logLevel;
+@property(nonatomic) NSString *uniqueId;
 @end
 
 @implementation FlutterBluePlugin
@@ -56,7 +57,6 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
   FlutterEventChannel* descriptorReadChannel = [FlutterEventChannel eventChannelWithName:NAMESPACE @"/descriptorRead" binaryMessenger:[registrar messenger]];
   FlutterBluePlugin* instance = [[FlutterBluePlugin alloc] init];
   instance.channel = channel;
-  instance.centralManager = [[CBCentralManager alloc] initWithDelegate:instance queue:nil];
   instance.scannedPeripherals = [NSMutableDictionary new];
   instance.servicesThatNeedDiscovered = [NSMutableArray new];
   instance.characteristicsThatNeedDiscovered = [NSMutableArray new];
@@ -90,13 +90,28 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
   [registrar addMethodCallDelegate:instance channel:channel];
 }
 
+- (CBCentralManager*)centralManager{
+  if (!_centralManager){
+    _centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil
+            options:_uniqueId ? @{CBCentralManagerOptionRestoreIdentifierKey: _uniqueId} : @{}];
+  }
+  return _centralManager;
+}
+
 - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
   if ([@"setLogLevel" isEqualToString:call.method]) {
     NSNumber *logLevelIndex = [call arguments];
     _logLevel = (LogLevel)[logLevelIndex integerValue];
     result(nil);
+  } else if([@"setUniqueId" isEqualToString:call.method]) {
+    _uniqueId = [call arguments];
+    if (!_centralManager){
+      result(@(YES));
+    } else {
+      result(@(NO));
+    }
   } else if ([@"state" isEqualToString:call.method]) {
-    FlutterStandardTypedData *data = [self toFlutterData:[self toBluetoothStateProto:self->_centralManager.state]];
+    FlutterStandardTypedData *data = [self toFlutterData:[self toBluetoothStateProto:self.centralManager.state]];
     result(data);
   } else if([@"isAvailable" isEqualToString:call.method]) {
     if(self.centralManager.state != CBManagerStateUnsupported && self.centralManager.state != CBManagerStateUnknown) {
@@ -123,10 +138,10 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
       uuids = [uuids arrayByAddingObject:[CBUUID UUIDWithString:u]];
     }
     // TODO: iOS Scan Options (#35)
-    [self->_centralManager scanForPeripheralsWithServices:uuids options:nil];
+    [self.centralManager scanForPeripheralsWithServices:uuids options:nil];
     result(nil);
   } else if([@"stopScan" isEqualToString:call.method]) {
-    [self->_centralManager stopScan];
+      [self.centralManager stopScan];
     result(nil);
   } else if([@"connect" isEqualToString:call.method]) {
     FlutterStandardTypedData *data = [call arguments];
@@ -140,7 +155,7 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
                                    details:nil];
       }
       // TODO: Implement Connect options (#36)
-      [_centralManager connectPeripheral:peripheral options:nil];
+      [self.centralManager connectPeripheral:peripheral options:nil];
       result(nil);
     } @catch(FlutterError *e) {
       result(e);
@@ -149,7 +164,7 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     NSString *remoteId = [call arguments];
     @try {
       CBPeripheral *peripheral = [self findPeripheral:remoteId];
-      [_centralManager cancelPeripheralConnection:peripheral];
+      [self.centralManager cancelPeripheralConnection:peripheral];
       result(nil);
     } @catch(FlutterError *e) {
       result(e);
@@ -268,7 +283,7 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
 }
 
 - (CBPeripheral*)findPeripheral:(NSString*)remoteId {
-  NSArray<CBPeripheral*> *peripherals = [_centralManager retrievePeripheralsWithIdentifiers:@[[[NSUUID alloc] initWithUUIDString:remoteId]]];
+  NSArray<CBPeripheral*> *peripherals = [self.centralManager retrievePeripheralsWithIdentifiers:@[[[NSUUID alloc] initWithUUIDString:remoteId]]];
   CBPeripheral *peripheral;
   for(CBPeripheral *p in peripherals) {
     if([[p.identifier UUIDString] isEqualToString:remoteId]) {
@@ -371,11 +386,15 @@ - (CBDescriptor*)getDescriptorFromArray:(NSString*)uuidString array:(NSArray<CBD
 //
 - (void)centralManagerDidUpdateState:(nonnull CBCentralManager *)central {
   if(_stateStreamHandler.sink != nil) {
-    FlutterStandardTypedData *data = [self toFlutterData:[self toBluetoothStateProto:self->_centralManager.state]];
+    FlutterStandardTypedData *data = [self toFlutterData:[self toBluetoothStateProto:self.centralManager.state]];
     self.stateStreamHandler.sink(data);
   }
 }
 
+- (void)centralManager:(CBCentralManager *)central willRestoreState:(NSDictionary<NSString *, id> *)dict {
+}
+
+
 - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *,id> *)advertisementData RSSI:(NSNumber *)RSSI {
   [self.scannedPeripherals setObject:peripheral
                               forKey:[[peripheral identifier] UUIDString]];
diff --git a/lib/src/flutter_blue.dart b/lib/src/flutter_blue.dart
index af42b66d..a069a39c 100644
--- a/lib/src/flutter_blue.dart
+++ b/lib/src/flutter_blue.dart
@@ -59,6 +59,10 @@ class FlutterBlue {
         .map((s) => BluetoothState.values[s.state.value]);
   }
 
+  /// Sets a unique id (required on iOS for restoring app on background-scan)
+  /// should be called before any other methods.
+  Future setUniqueId(String uniqueid) => _channel.invokeMethod('setUniqueId',uniqueid.toString());
+  
   /// Starts a scan for Bluetooth Low Energy devices
   /// Timeout closes the stream after a specified [Duration]
   Stream<ScanResult> scan({