diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index 8e1804f7..0defed9e 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -50,11 +50,13 @@
 
         <service
                 android:name=".ShadowsocksService"
-                android:enabled="true"/>
+                android:process=":proxy"
+                android:exported="false"/>
 
         <service
                 android:name=".ShadowVpnService"
                 android:label="@string/app_name"
+                android:process=":vpn"
                 android:permission="android.permission.BIND_VPN_SERVICE"
                 android:exported="false">
             <intent-filter>
diff --git a/src/main/java/com/github/shadowsocks/IStateService.aidl b/src/main/java/com/github/shadowsocks/IStateService.aidl
new file mode 100644
index 00000000..f2b336f8
--- /dev/null
+++ b/src/main/java/com/github/shadowsocks/IStateService.aidl
@@ -0,0 +1,6 @@
+package com.github.shadowsocks;
+
+interface IStateService {
+  int getState();
+  String getMessage();
+}
diff --git a/src/main/res/drawable-hdpi/ic_launcher.png b/src/main/res/drawable-hdpi/ic_launcher.png
index 810bd7c1..4a7bd7f1 100755
Binary files a/src/main/res/drawable-hdpi/ic_launcher.png and b/src/main/res/drawable-hdpi/ic_launcher.png differ
diff --git a/src/main/res/drawable-mdpi/ic_launcher.png b/src/main/res/drawable-mdpi/ic_launcher.png
index 0927af4b..5ce8d4b5 100755
Binary files a/src/main/res/drawable-mdpi/ic_launcher.png and b/src/main/res/drawable-mdpi/ic_launcher.png differ
diff --git a/src/main/res/drawable-xhdpi/ic_launcher.png b/src/main/res/drawable-xhdpi/ic_launcher.png
index 4529102e..7b5db8e2 100755
Binary files a/src/main/res/drawable-xhdpi/ic_launcher.png and b/src/main/res/drawable-xhdpi/ic_launcher.png differ
diff --git a/src/main/res/drawable-xxhdpi/ic_launcher.png b/src/main/res/drawable-xxhdpi/ic_launcher.png
index 45b16668..c5c0ea13 100755
Binary files a/src/main/res/drawable-xxhdpi/ic_launcher.png and b/src/main/res/drawable-xxhdpi/ic_launcher.png differ
diff --git a/src/main/scala/com/github/shadowsocks/ShadowVpnService.scala b/src/main/scala/com/github/shadowsocks/ShadowVpnService.scala
index 4bebbebc..d7359996 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowVpnService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowVpnService.scala
@@ -47,25 +47,15 @@ import android.support.v4.app.NotificationCompat
 import android.util.Log
 import com.google.analytics.tracking.android.EasyTracker
 import java.io._
-import java.lang.ref.WeakReference
 import android.net.VpnService
 import org.apache.http.conn.util.InetAddressUtils
 import android.os.Message
 import scala.Some
 
 object ShadowVpnService {
-  def isServiceStarted: Boolean = {
-    if (sRunningInstance == null) {
-      false
-    } else if (sRunningInstance.get == null) {
-      sRunningInstance = null
-      false
-    } else {
-      true
-    }
+  def isServiceStarted(context: Context): Boolean = {
+    Utils.isServiceStarted("com.github.shadowsocks.ShadowVpnService", context)
   }
-
-  var sRunningInstance: WeakReference[ShadowVpnService] = null
 }
 
 class ShadowVpnService extends VpnService {
@@ -73,13 +63,12 @@ class ShadowVpnService extends VpnService {
   val TAG = "ShadowVpnService"
   val BASE = "/data/data/com.github.shadowsocks/"
   val SHADOWSOCKS_CONF = "{\"server\": [%s], \"server_port\": %d, \"local_port\": %d, \"password\": %s, \"timeout\": %d}"
-  val MSG_CONNECT_START: Int = 0
-  val MSG_CONNECT_FINISH: Int = 1
-  val MSG_CONNECT_SUCCESS: Int = 2
-  val MSG_CONNECT_FAIL: Int = 3
-  val MSG_HOST_CHANGE: Int = 4
-  val MSG_STOP_SELF: Int = 5
-  val MSG_VPN_ERROR: Int = 6
+  val MSG_CONNECT_START = 0
+  val MSG_CONNECT_FINISH = 1
+  val MSG_CONNECT_SUCCESS = 2
+  val MSG_CONNECT_FAIL = 3
+  val MSG_STOP_SELF = 5
+  val MSG_VPN_ERROR = 6
 
   val VPN_MTU = 1500
 
@@ -103,26 +92,39 @@ class ShadowVpnService extends VpnService {
   var encMethod: String = null
   var apps: Array[ProxiedApp] = null
 
+  private var state = State.INIT
+  private var message: String = null
+
+  def changeState(s: Int) {
+    changeState(s, null)
+  }
+
+  def changeState(s: Int, m: String) {
+    if (state != s) {
+      state = s
+      if (m != null) message = m
+      sendBroadcast(new Intent(Utils.ACTION_UPDATE_STATE))
+    }
+  }
+
   val handler: Handler = new Handler {
     override def handleMessage(msg: Message) {
       val ed: SharedPreferences.Editor = settings.edit
       msg.what match {
         case MSG_CONNECT_START =>
-          ed.putBoolean("isConnecting", true)
-          ed.remove("vpnError")
-        case MSG_CONNECT_FINISH =>
-          ed.putBoolean("isConnecting", false)
+          changeState(State.CONNECTING)
         case MSG_CONNECT_SUCCESS =>
+          changeState(State.CONNECTED)
           ed.putBoolean("isRunning", true)
         case MSG_CONNECT_FAIL =>
+          changeState(State.FAILED)
           ed.putBoolean("isRunning", false)
-        case MSG_HOST_CHANGE =>
-          ed.putString("appHost", appHost)
         case MSG_VPN_ERROR =>
-          if (msg.obj != null) ed.putString("vpnError", msg.obj.asInstanceOf[String])
+          if (msg.obj != null) changeState(State.FAILED, msg.obj.asInstanceOf[String])
         case MSG_STOP_SELF =>
           destroy()
           stopSelf()
+        case _ =>
       }
       ed.commit
       super.handleMessage(msg)
@@ -248,7 +250,6 @@ class ShadowVpnService extends VpnService {
         handler.sendEmptyMessageDelayed(MSG_CONNECT_FINISH, 300)
       }
     }).start()
-    markServiceStarted()
   }
 
   def waitForProcess(name: String): Boolean = {
@@ -362,14 +363,6 @@ class ShadowVpnService extends VpnService {
     notification.defaults |= Notification.DEFAULT_LIGHTS
   }
 
-  def markServiceStarted() {
-    ShadowVpnService.sRunningInstance = new WeakReference[ShadowVpnService](this)
-  }
-
-  def markServiceStopped() {
-    ShadowVpnService.sRunningInstance = null
-  }
-
   def notifyAlert(title: String, info: String) {
     val openIntent: Intent = new Intent(this, classOf[Shadowsocks])
     openIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
@@ -391,7 +384,16 @@ class ShadowVpnService extends VpnService {
     if (VpnService.SERVICE_INTERFACE == action) {
       return super.onBind(intent)
     }
-    null
+
+    new IStateService.Stub {
+      def getMessage: String = {
+        val m = message
+        message = null
+        m
+      }
+
+      def getState: Int = state
+    }
   }
 
   override def onCreate() {
@@ -405,7 +407,7 @@ class ShadowVpnService extends VpnService {
     // register close receiver
     val filter = new IntentFilter()
     filter.addAction(Intent.ACTION_SHUTDOWN)
-    filter.addAction(Utils.CLOSE_ACTION)
+    filter.addAction(Utils.ACTION_CLOSE)
     receiver = new BroadcastReceiver {
       def onReceive(p1: Context, p2: Intent) {
         destroy()
@@ -416,6 +418,7 @@ class ShadowVpnService extends VpnService {
   }
 
   def destroy() {
+    changeState(State.STOPPED)
     EasyTracker.getTracker.sendEvent(TAG, "stop", getVersionName, 0L)
     if (receiver != null) {
       unregisterReceiver(receiver)
@@ -428,22 +431,20 @@ class ShadowVpnService extends VpnService {
     }.start()
     val ed: SharedPreferences.Editor = settings.edit
     ed.putBoolean("isRunning", false)
-    ed.putBoolean("isConnecting", false)
     ed.commit
     if (conn != null) {
       conn.close()
       conn = null
     }
     notificationManager.cancel(1)
-    markServiceStopped()
   }
 
   /** Called when the activity is closed. */
   override def onDestroy() {
-    super.onDestroy()
     EasyTracker.getTracker.setStartSession(false)
     EasyTracker.getTracker.sendEvent(TAG, "stop", getVersionName, 0L)
     destroy()
+    super.onDestroy()
   }
 
   def killProcesses() {
diff --git a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
index cca32fc2..93cf4e96 100644
--- a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
+++ b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
@@ -38,14 +38,10 @@
 package com.github.shadowsocks
 
 import android.app.{Activity, AlertDialog, ProgressDialog}
-import android.content.Context
-import android.content.DialogInterface
-import android.content.Intent
-import android.content.SharedPreferences
-import android.content.SharedPreferences.OnSharedPreferenceChangeListener
+import android.content._
 import android.content.res.AssetManager
 import android.graphics.Typeface
-import android.os.{Build, Bundle, Handler, Message}
+import android.os._
 import android.preference.Preference
 import android.preference.PreferenceManager
 import android.util.Log
@@ -79,11 +75,17 @@ object Shadowsocks {
   val TAG = "Shadowsocks"
   val REQUEST_CONNECT = 1
 
-  class ProxyFragment extends UnifiedPreferenceFragment with OnSharedPreferenceChangeListener {
+  def isServiceStarted(context: Context): Boolean = {
+    ShadowsocksService.isServiceStarted(context) || ShadowVpnService.isServiceStarted(context)
+  }
+
+  class ProxyFragment extends UnifiedPreferenceFragment {
+
+    var receiver: BroadcastReceiver = null
+
     private def setPreferenceEnabled() {
-      val settings: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity)
-      val enabled: Boolean = !settings.getBoolean("isRunning", false) &&
-        !settings.getBoolean("isConnecting", false)
+      val state = getActivity.asInstanceOf[Shadowsocks].state
+      val enabled: Boolean = state != State.CONNECTED && state != State.CONNECTING
       for (name <- PROXY_PREFS) {
         val pref: Preference = findPreference(name)
         if (pref != null) {
@@ -92,32 +94,44 @@ object Shadowsocks {
       }
     }
 
+    override def onStart() {
+      super.onStart()
+      val filter = new IntentFilter()
+      filter.addAction(Utils.ACTION_UPDATE_FRAGMENT)
+      receiver = new BroadcastReceiver {
+        def onReceive(p1: Context, p2: Intent) {
+          setPreferenceEnabled()
+        }
+      }
+      getActivity.getApplicationContext.registerReceiver(receiver, filter)
+    }
+
+    override def onStop() {
+      super.onStop()
+      getActivity.getApplicationContext.unregisterReceiver(receiver)
+    }
+
     override def onResume() {
       super.onResume()
       setPreferenceEnabled()
-      getPreferenceScreen.getSharedPreferences.registerOnSharedPreferenceChangeListener(this)
     }
 
     override def onPause() {
       super.onPause()
-      getPreferenceScreen.getSharedPreferences.unregisterOnSharedPreferenceChangeListener(this)
-    }
-
-    def onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
-      if ((key == "isRunning") || (key == "isGlobalProxy")) {
-        setPreferenceEnabled()
-      }
     }
   }
 
-  class FeatureFragment extends UnifiedPreferenceFragment with OnSharedPreferenceChangeListener {
+  class FeatureFragment extends UnifiedPreferenceFragment {
+
+    var receiver: BroadcastReceiver = null
+
     private def setPreferenceEnabled() {
-      val settings: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity)
-      val enabled: Boolean = !settings.getBoolean("isRunning", false) &&
-        !settings.getBoolean("isConnecting", false)
+      val state = getActivity.asInstanceOf[Shadowsocks].state
+      val enabled: Boolean = state != State.CONNECTED && state != State.CONNECTING
       for (name <- Shadowsocks.FEATRUE_PREFS) {
         val pref: Preference = findPreference(name)
         if (pref != null) {
+          val settings = PreferenceManager.getDefaultSharedPreferences(getActivity)
           if ((name == "isBypassApps") || (name == "proxyedApps")) {
             val isGlobalProxy: Boolean = settings.getBoolean("isGlobalProxy", false)
             pref.setEnabled(enabled && !isGlobalProxy)
@@ -130,21 +144,30 @@ object Shadowsocks {
       }
     }
 
+    override def onStart() {
+      super.onStart()
+      val filter = new IntentFilter()
+      filter.addAction(Utils.ACTION_UPDATE_FRAGMENT)
+      receiver = new BroadcastReceiver {
+        def onReceive(p1: Context, p2: Intent) {
+          setPreferenceEnabled()
+        }
+      }
+      getActivity.getApplicationContext.registerReceiver(receiver, filter)
+    }
+
+    override def onStop() {
+      super.onStop()
+      getActivity.getApplicationContext.unregisterReceiver(receiver)
+    }
+
     override def onResume() {
       super.onResume()
       setPreferenceEnabled()
-      getPreferenceScreen.getSharedPreferences.registerOnSharedPreferenceChangeListener(this)
     }
 
     override def onPause() {
       super.onPause()
-      getPreferenceScreen.getSharedPreferences.unregisterOnSharedPreferenceChangeListener(this)
-    }
-
-    def onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
-      if ((key == "isRunning") || (key == "isGlobalProxy")) {
-        setPreferenceEnabled()
-      }
     }
   }
 
@@ -173,20 +196,34 @@ object Typefaces {
 }
 
 class Shadowsocks
-  extends UnifiedSherlockPreferenceActivity with CompoundButton.OnCheckedChangeListener with
-  OnSharedPreferenceChangeListener {
+  extends UnifiedSherlockPreferenceActivity
+  with CompoundButton.OnCheckedChangeListener {
 
   private val MSG_CRASH_RECOVER: Int = 1
   private val MSG_INITIAL_FINISH: Int = 2
 
   private var switchButton: Switch = null
   private var progressDialog: ProgressDialog = null
+  private var settings: SharedPreferences = null
   private var prepared = false
+  private var state = State.INIT
+  private var binder: IStateService = null
+  private var receiver: StateBroadcastReceiver = null
+
+  private val connection = new ServiceConnection {
+    def onServiceDisconnected(name: ComponentName) {
+      onStateChanged(binder.getState, binder.getMessage)
+      binder = null
+    }
+
+    def onServiceConnected(name: ComponentName, s: IBinder) {
+      binder = IStateService.Stub.asInterface(s)
+      onStateChanged(binder.getState, binder.getMessage)
+    }
+  }
 
   private val handler: Handler = new Handler {
     override def handleMessage(msg: Message) {
-      val settings: SharedPreferences = PreferenceManager
-        .getDefaultSharedPreferences(Shadowsocks.this)
       val ed: SharedPreferences.Editor = settings.edit
       msg.what match {
         case MSG_CRASH_RECOVER =>
@@ -326,13 +363,14 @@ class Shadowsocks
     getSupportActionBar.setDisplayShowTitleEnabled(false)
     getSupportActionBar.setDisplayShowCustomEnabled(true)
     getSupportActionBar.setDisplayShowHomeEnabled(false)
+
     switchButton = switchLayout.findViewById(R.id.switchButton).asInstanceOf[Switch]
     val title: TextView = switchLayout.findViewById(R.id.title).asInstanceOf[TextView]
     val tf: Typeface = Typefaces.get(this, "fonts/Iceland.ttf")
     if (tf != null) title.setTypeface(tf)
     title.setText(R.string.app_name)
-    val settings: SharedPreferences = PreferenceManager
-      .getDefaultSharedPreferences(Shadowsocks.this)
+    settings = PreferenceManager.getDefaultSharedPreferences(this)
+
     val init: Boolean = !settings.getBoolean("isRunning", false) &&
       !settings.getBoolean("isConnecting", false)
     if (init) {
@@ -412,29 +450,30 @@ class Shadowsocks
   protected override def onPause() {
     super.onPause()
     prepared = false
-    PreferenceManager
-      .getDefaultSharedPreferences(this)
-      .unregisterOnSharedPreferenceChangeListener(this)
   }
 
   protected override def onResume() {
     super.onResume()
     if (!prepared) {
-      val settings: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)
-      if (isServiceStarted) {
+      if (Shadowsocks.isServiceStarted(this)) {
         switchButton.setChecked(true)
-        if (ShadowVpnService.isServiceStarted) {
+        if (ShadowVpnService.isServiceStarted(this)) {
           val style = new Style.Builder()
             .setBackgroundColorValue(Style.holoBlueLight)
             .setDuration(Style.DURATION_INFINITE)
             .build()
           switchButton.setEnabled(false)
           Crouton.makeText(Shadowsocks.this, R.string.vpn_status, style).show()
+          if (binder == null) bindService(new Intent(this, classOf[ShadowVpnService]), connection, 0)
+        } else {
+          if (binder == null) bindService(new Intent(this, classOf[ShadowsocksService]), connection, 0)
         }
+        setPreferenceEnabled(false)
       } else {
         switchButton.setEnabled(true)
         switchButton.setChecked(false)
         Crouton.cancelAllCroutons()
+        setPreferenceEnabled(true)
         if (settings.getBoolean("isRunning", false)) {
           new Thread {
             override def run() {
@@ -445,18 +484,11 @@ class Shadowsocks
         }
       }
     }
-    setPreferenceEnabled()
+
     switchButton.setOnCheckedChangeListener(this)
-    PreferenceManager
-      .getDefaultSharedPreferences(this)
-      .registerOnSharedPreferenceChangeListener(this)
   }
 
-  private def setPreferenceEnabled() {
-    val settings: SharedPreferences = PreferenceManager
-      .getDefaultSharedPreferences(Shadowsocks.this)
-    val enabled: Boolean = !settings.getBoolean("isRunning", false) &&
-      !settings.getBoolean("isConnecting", false)
+  private def setPreferenceEnabled(enabled: Boolean) {
     for (name <- Shadowsocks.PROXY_PREFS) {
       val pref: Preference = findPreference(name)
       if (pref != null) {
@@ -478,54 +510,16 @@ class Shadowsocks
     }
   }
 
-  def onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
-    val settings: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)
-    if ((key == "isConnecting" || key == "isRunning")
-      && !settings.getBoolean("isConnecting", false)) {
-      if (settings.getBoolean("isRunning", false)) {
-        if (!switchButton.isChecked) switchButton.setChecked(true)
-      } else {
-        if (switchButton.isChecked) {
-          switchButton.setEnabled(true)
-          switchButton.setChecked(false)
-          Crouton.cancelAllCroutons()
-        }
-
-        val msg = settings.getString("vpnError", null)
-        if (msg != null) {
-          Crouton.cancelAllCroutons()
-          val style = new Style.Builder()
-            .setBackgroundColorValue(Style.holoRedLight)
-            .setDuration(Style.DURATION_INFINITE)
-            .build()
-          Crouton.makeText(this, getString(R.string.vpn_error).format(msg), style).show()
-        }
-      }
-    }
-    if (key == "isConnecting") {
-      if (settings.getBoolean("isConnecting", false)) {
-        if (progressDialog == null) {
-          progressDialog = ProgressDialog.show(this, "", getString(R.string.connecting), true, true)
-        }
-      } else {
-        if (progressDialog != null) {
-          progressDialog.dismiss()
-          progressDialog = null
-        }
-      }
-    }
-    if ((key == "isRunning") || (key == "isGlobalProxy")) {
-      setPreferenceEnabled()
-    }
-  }
-
   override def onStart() {
     super.onStart()
+    receiver = new StateBroadcastReceiver()
+    registerReceiver(receiver, new IntentFilter(Utils.ACTION_UPDATE_STATE))
     EasyTracker.getInstance.activityStart(this)
   }
 
   override def onStop() {
     super.onStop()
+    unregisterReceiver(receiver)
     EasyTracker.getInstance.activityStop(this)
     if (progressDialog != null) {
       progressDialog.dismiss()
@@ -536,6 +530,7 @@ class Shadowsocks
   override def onDestroy() {
     super.onDestroy()
     Crouton.cancelAllCroutons()
+    if (binder != null) unbindService(connection)
   }
 
   def reset() {
@@ -589,23 +584,18 @@ class Shadowsocks
     Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH && !Utils.getRoot
   }
 
-  def isServiceStarted: Boolean = {
-    ShadowsocksService.isServiceStarted || ShadowVpnService.isServiceStarted
-  }
-
   def serviceStop() {
-    if (ShadowVpnService.isServiceStarted) {
+    if (ShadowVpnService.isServiceStarted(this)) {
       stopService(new Intent(this, classOf[ShadowVpnService]))
     }
-    if (ShadowsocksService.isServiceStarted) {
-      sendBroadcast(new Intent(Utils.CLOSE_ACTION))
+    if (ShadowsocksService.isServiceStarted(this)) {
+      sendBroadcast(new Intent(Utils.ACTION_CLOSE))
     }
   }
 
   /** Called when connect button is clicked. */
   def serviceStart: Boolean = {
 
-    val settings: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)
     val proxy = settings.getString("proxy", "")
     if (isTextEmpty(proxy, getString(R.string.proxy_empty))) return false
     val portText = settings.getString("port", "")
@@ -624,9 +614,10 @@ class Shadowsocks
     }
 
     if (isVpnEnabled) {
-      if (ShadowVpnService.isServiceStarted) return false
+      if (ShadowVpnService.isServiceStarted(this)) return false
       val it: Intent = new Intent(this, classOf[ShadowVpnService])
       startService(it)
+      bindService(it, connection, 0)
       val style = new Style.Builder()
         .setBackgroundColorValue(Style.holoBlueLight)
         .setDuration(Style.DURATION_INFINITE)
@@ -634,11 +625,11 @@ class Shadowsocks
       Crouton.makeText(Shadowsocks.this, R.string.vpn_status, style).show()
       switchButton.setEnabled(false)
     } else {
-      if (ShadowsocksService.isServiceStarted) return false
+      if (ShadowsocksService.isServiceStarted(this)) return false
       val it: Intent = new Intent(this, classOf[ShadowsocksService])
       startService(it)
+      bindService(it, connection, 0)
     }
-
     true
   }
 
@@ -688,4 +679,64 @@ class Shadowsocks
     val alert: AlertDialog = builder.create
     alert.show()
   }
+
+  def clearDialog() {
+    if (progressDialog != null) {
+      progressDialog.dismiss()
+      progressDialog = null
+    }
+  }
+
+  def onStateChanged(s: Int, m: String) {
+    if (state != s) {
+      state = s
+      state match {
+        case State.CONNECTING => {
+          if (progressDialog == null) {
+            progressDialog = ProgressDialog.show(Shadowsocks.this, "", getString(R.string.connecting), true, true)
+          }
+          setPreferenceEnabled(false)
+        }
+        case State.CONNECTED => {
+          clearDialog()
+          if (!switchButton.isChecked) switchButton.setChecked(true)
+          setPreferenceEnabled(false)
+        }
+        case State.FAILED => {
+          clearDialog()
+          if (switchButton.isChecked) {
+            switchButton.setEnabled(true)
+            switchButton.setChecked(false)
+            Crouton.cancelAllCroutons()
+          }
+          if (m != null) {
+            Crouton.cancelAllCroutons()
+            val style = new Style.Builder()
+              .setBackgroundColorValue(Style.holoRedLight)
+              .setDuration(Style.DURATION_INFINITE)
+              .build()
+            Crouton.makeText(Shadowsocks.this, getString(R.string.vpn_error).format(m), style).show()
+          }
+          setPreferenceEnabled(true)
+        }
+        case State.STOPPED => {
+          clearDialog()
+          Crouton.cancelAllCroutons()
+          if (switchButton.isChecked) switchButton.setChecked(false)
+          setPreferenceEnabled(true)
+        }
+      }
+      sendBroadcast(new Intent(Utils.ACTION_UPDATE_FRAGMENT))
+    }
+  }
+
+  class StateBroadcastReceiver extends BroadcastReceiver {
+    override def onReceive(context: Context, intent: Intent) {
+      if (binder != null) {
+        val s = binder.getState
+        val m = binder.getMessage
+        onStateChanged(s, m)
+      }
+    }
+  }
 }
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksReceiver.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksReceiver.scala
index dc2c335b..fb76545e 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksReceiver.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksReceiver.scala
@@ -77,7 +77,7 @@ class ShadowsocksReceiver extends BroadcastReceiver {
       }
 
       if (Utils.getRoot) {
-        if (ShadowsocksService.isServiceStarted) return
+        if (ShadowsocksService.isServiceStarted(context)) return
         val it: Intent = new Intent(context, classOf[ShadowsocksService])
         context.startService(it)
       }
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksService.scala
index 5d0a53f7..84ab5ca4 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksService.scala
@@ -44,10 +44,7 @@ import android.app.Service
 import android.content._
 import android.content.pm.PackageInfo
 import android.content.pm.PackageManager
-import android.os.Handler
-import android.os.IBinder
-import android.os.Message
-import android.os.PowerManager
+import android.os._
 import android.preference.PreferenceManager
 import android.support.v4.app.NotificationCompat
 import android.util.Log
@@ -56,7 +53,6 @@ import java.io.BufferedReader
 import java.io.FileNotFoundException
 import java.io.FileReader
 import java.io.IOException
-import java.lang.ref.WeakReference
 import java.lang.reflect.InvocationTargetException
 import java.lang.reflect.Method
 import org.apache.http.conn.util.InetAddressUtils
@@ -64,18 +60,9 @@ import scala.collection._
 import scala.Some
 
 object ShadowsocksService {
-  def isServiceStarted: Boolean = {
-    if (sRunningInstance == null) {
-      false
-    } else if (sRunningInstance.get == null) {
-      sRunningInstance = null
-      false
-    } else {
-      true
-    }
+  def isServiceStarted(context: Context): Boolean = {
+    Utils.isServiceStarted("com.github.shadowsocks.ShadowsocksService", context)
   }
-
-  var sRunningInstance: WeakReference[ShadowsocksService] = null
 }
 
 class ShadowsocksService extends Service {
@@ -101,13 +88,14 @@ class ShadowsocksService extends Service {
   val CMD_IPTABLES_REDIRECT_ADD_SOCKS = " -t nat -A OUTPUT -p tcp " + "-j REDIRECT --to 8123\n"
   val CMD_IPTABLES_DNAT_ADD_SOCKS = " -t nat -A OUTPUT -p tcp " +
     "-j DNAT --to-destination 127.0.0.1:8123\n"
-  val MSG_CONNECT_START: Int = 0
-  val MSG_CONNECT_FINISH: Int = 1
-  val MSG_CONNECT_SUCCESS: Int = 2
-  val MSG_CONNECT_FAIL: Int = 3
-  val MSG_HOST_CHANGE: Int = 4
-  val MSG_STOP_SELF: Int = 5
-  val DNS_PORT: Int = 8153
+  val DNS_PORT = 8153
+
+  val MSG_CONNECT_START = 0
+  val MSG_CONNECT_FINISH = 1
+  val MSG_CONNECT_SUCCESS = 2
+  val MSG_CONNECT_FAIL = 3
+  val MSG_STOP_SELF = 4
+  val MSG_VPN_ERROR = 5
 
   val mStartForegroundSignature = Array[Class[_]](classOf[Int], classOf[Notification])
   val mStopForegroundSignature = Array[Class[_]](classOf[Boolean])
@@ -115,7 +103,6 @@ class ShadowsocksService extends Service {
 
   var receiver: BroadcastReceiver = null
   var notificationManager: NotificationManager = null
-  var mWakeLock: PowerManager#WakeLock = null
   var appHost: String = null
   var remotePort: Int = 0
   var localPort: Int = 0
@@ -136,6 +123,36 @@ class ShadowsocksService extends Service {
   var mStartForegroundArgs = new Array[AnyRef](2)
   var mStopForegroundArgs = new Array[AnyRef](1)
 
+  private var state = State.INIT
+
+  private def changeState(s: Int) {
+    if (state != s) {
+      state = s
+      sendBroadcast(new Intent(Utils.ACTION_UPDATE_STATE))
+    }
+  }
+
+  val handler: Handler = new Handler {
+    override def handleMessage(msg: Message) {
+      val ed: SharedPreferences.Editor = settings.edit
+      msg.what match {
+        case MSG_CONNECT_START =>
+          changeState(State.CONNECTING)
+        case MSG_CONNECT_SUCCESS =>
+          changeState(State.CONNECTED)
+          ed.putBoolean("isRunning", true)
+        case MSG_CONNECT_FAIL =>
+          changeState(State.FAILED)
+          ed.putBoolean("isRunning", false)
+        case MSG_STOP_SELF =>
+          stopSelf()
+        case _ =>
+      }
+      ed.commit
+      super.handleMessage(msg)
+    }
+  }
+
   def getPid(name: String): Int = {
     try {
       val reader: BufferedReader = new BufferedReader(new FileReader(BASE + name + ".pid"))
@@ -263,7 +280,6 @@ class ShadowsocksService extends Service {
         handler.sendEmptyMessageDelayed(MSG_CONNECT_FINISH, 500)
       }
     }).start()
-    markServiceStarted()
   }
 
   def startRedsocksDaemon() {
@@ -321,19 +337,11 @@ class ShadowsocksService extends Service {
     }
   }
 
-  def markServiceStarted() {
-    ShadowsocksService.sRunningInstance = new WeakReference[ShadowsocksService](this)
-  }
-
-  def markServiceStopped() {
-    ShadowsocksService.sRunningInstance = null
-  }
-
   def notifyForegroundAlert(title: String, info: String) {
     val openIntent: Intent = new Intent(this, classOf[Shadowsocks])
     openIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
     val contentIntent: PendingIntent = PendingIntent.getActivity(this, 0, openIntent, 0)
-    val closeIntent: Intent = new Intent(Utils.CLOSE_ACTION)
+    val closeIntent: Intent = new Intent(Utils.ACTION_CLOSE)
     val actionIntent: PendingIntent = PendingIntent.getBroadcast(this, 0, closeIntent, 0)
     val builder: NotificationCompat.Builder = new NotificationCompat.Builder(this)
     builder
@@ -365,7 +373,10 @@ class ShadowsocksService extends Service {
   }
 
   def onBind(intent: Intent): IBinder = {
-    null
+    new IStateService.Stub {
+      def getMessage: String = null
+      def getState: Int = state
+    }
   }
 
   override def onCreate() {
@@ -399,7 +410,7 @@ class ShadowsocksService extends Service {
     // register close receiver
     val filter = new IntentFilter()
     filter.addAction(Intent.ACTION_SHUTDOWN)
-    filter.addAction(Utils.CLOSE_ACTION)
+    filter.addAction(Utils.ACTION_CLOSE)
     receiver = new BroadcastReceiver() {
       def onReceive(p1: Context, p2: Intent) {
         stopSelf()
@@ -410,7 +421,7 @@ class ShadowsocksService extends Service {
 
   /** Called when the activity is closed. */
   override def onDestroy() {
-    super.onDestroy()
+    changeState(State.STOPPED)
     EasyTracker.getTracker.setStartSession(false)
     EasyTracker.getTracker.sendEvent(TAG, "stop", getVersionName, 0L)
     stopForegroundCompat(1)
@@ -421,13 +432,12 @@ class ShadowsocksService extends Service {
     }.start()
     val ed: SharedPreferences.Editor = settings.edit
     ed.putBoolean("isRunning", false)
-    ed.putBoolean("isConnecting", false)
     ed.commit
-    markServiceStopped()
     if (receiver != null) {
       unregisterReceiver(receiver)
       receiver = null
     }
+    super.onDestroy()
   }
 
   def killProcesses() {
@@ -572,31 +582,5 @@ class ShadowsocksService extends Service {
     invokeMethod(mSetForeground, mSetForegroundArgs)
   }
 
-  val handler: Handler = new Handler {
-    override def handleMessage(msg: Message) {
-      val ed: SharedPreferences.Editor = settings.edit
-      msg.what match {
-        case MSG_CONNECT_START =>
-          ed.putBoolean("isConnecting", true)
-          val pm: PowerManager = getSystemService(Context.POWER_SERVICE).asInstanceOf[PowerManager]
-          mWakeLock = pm
-            .newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE,
-            "GAEProxy")
-          mWakeLock.acquire()
-        case MSG_CONNECT_FINISH =>
-          ed.putBoolean("isConnecting", false)
-          if (mWakeLock != null && mWakeLock.isHeld) mWakeLock.release()
-        case MSG_CONNECT_SUCCESS =>
-          ed.putBoolean("isRunning", true)
-        case MSG_CONNECT_FAIL =>
-          ed.putBoolean("isRunning", false)
-        case MSG_HOST_CHANGE =>
-          ed.putString("appHost", appHost)
-        case MSG_STOP_SELF =>
-          stopSelf()
-      }
-      ed.commit
-      super.handleMessage(msg)
-    }
-  }
+
 }
diff --git a/src/main/scala/com/github/shadowsocks/Utils.scala b/src/main/scala/com/github/shadowsocks/Utils.scala
index 3cffe1e4..f30218b5 100644
--- a/src/main/scala/com/github/shadowsocks/Utils.scala
+++ b/src/main/scala/com/github/shadowsocks/Utils.scala
@@ -50,10 +50,22 @@ import scala.collection.mutable.ArrayBuffer
 import org.xbill.DNS._
 import scala.Some
 import android.graphics.{Canvas, Bitmap}
+import android.app.ActivityManager
+
+object State {
+  val INIT = 0
+  val CONNECTED = 1
+  val CONNECTING = 2
+  val FAILED = 3
+  val STOPPED = 4
+}
 
 object Utils {
 
-  val CLOSE_ACTION = "com.github.shadowsocks.ACTION_SHUTDOWN"
+  val ACTION_CLOSE = "com.github.shadowsocks.ACTION_SHUTDOWN"
+  val ACTION_UPDATE_STATE = "com.github.shadowsocks.ACTION_UPDATE_STATE"
+  val ACTION_UPDATE_FRAGMENT = "com.github.shadowsocks.ACTION_UPDATE_FRAGMENT"
+
   val TAG: String = "Shadowsocks"
   val ABI_PROP: String = "ro.product.cpu.abi"
   val ABI2_PROP: String = "ro.product.cpu.abi2"
@@ -75,6 +87,21 @@ object Utils {
   var data_path: String = null
   var rootTries = 0
 
+  def isServiceStarted(name: String, context: Context): Boolean = {
+    import scala.collection.JavaConversions._
+
+    val activityManager = context.getSystemService(Context.ACTIVITY_SERVICE).asInstanceOf[ActivityManager]
+    val services = activityManager.getRunningServices(Integer.MAX_VALUE)
+
+    for (service <- services) {
+      if (service.service.getClassName == name) {
+        return true
+      }
+    }
+
+    false
+  }
+
   def resolve(host: String, addrType: Int): Option[String] = {
     val lookup = new Lookup(host, addrType)
     val resolver = new SimpleResolver("8.8.8.8")