diff --git a/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt b/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
index 6209ae0..5142a41 100644
--- a/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
+++ b/app/src/main/java/io/github/chronosx88/yggdrasil/MainActivity.kt
@@ -3,8 +3,6 @@ package io.github.chronosx88.yggdrasil
 import android.app.Activity
 import android.app.ActivityManager
 import android.content.*
-import android.net.ConnectivityManager
-import android.net.Network
 import android.net.VpnService
 import android.os.Build
 import android.os.Bundle
@@ -13,12 +11,12 @@ import android.view.Gravity
 import android.view.View
 import android.widget.*
 import androidx.appcompat.app.AppCompatActivity
+import androidx.appcompat.widget.SwitchCompat
 import androidx.preference.PreferenceManager
 import dalvik.system.DexFile
 import io.github.chronosx88.yggdrasil.models.DNSInfo
 import io.github.chronosx88.yggdrasil.models.PeerInfo
 import io.github.chronosx88.yggdrasil.models.config.DNSInfoListAdapter
-import io.github.chronosx88.yggdrasil.models.config.NetworkUtils
 import io.github.chronosx88.yggdrasil.models.config.PeerInfoListAdapter
 import io.github.chronosx88.yggdrasil.models.config.Utils.Companion.deserializePeerStringList2PeerInfoSet
 import io.github.chronosx88.yggdrasil.models.config.Utils.Companion.deserializeStringList2DNSInfoSet
@@ -74,7 +72,7 @@ class MainActivity : AppCompatActivity() {
         setContentView(R.layout.activity_main)
         setSupportActionBar(findViewById(R.id.toolbar))
         isStarted = isYggServiceRunning(this)
-        val switchOn = findViewById<Switch>(R.id.switchOn)
+        val switchOn = findViewById<SwitchCompat>(R.id.switchOn)
         switchOn.isChecked = isStarted
 
         switchOn.setOnCheckedChangeListener { _, isChecked ->
@@ -92,12 +90,17 @@ class MainActivity : AppCompatActivity() {
         //save to shared preferences
         val preferences =
             PreferenceManager.getDefaultSharedPreferences(this.baseContext)
-        val staticIP = findViewById<Switch>(R.id.staticIP)
+        val staticIP = findViewById<SwitchCompat>(R.id.staticIP)
         staticIP.isChecked =
             preferences.getString(STATIC_IP, null) != null
         val peersListView = findViewById<ListView>(R.id.peers)
 
-        currentPeers = deserializeStringSet2PeerInfoSet(preferences.getStringSet(CURRENT_PEERS, HashSet())!!)
+        currentPeers = deserializeStringSet2PeerInfoSet(
+            preferences.getStringSet(
+                CURRENT_PEERS,
+                HashSet()
+            )!!
+        )
         val adapter = PeerInfoListAdapter(this, currentPeers.sortedWith(compareBy { it.ping }))
         peersListView.adapter = adapter
         if(isStarted && this.currentPeers.isEmpty()) {
@@ -125,7 +128,12 @@ class MainActivity : AppCompatActivity() {
         }
 
         val listViewDNS = findViewById<ListView>(R.id.dns)
-        currentDNS = deserializeStringSet2DNSInfoSet(preferences.getStringSet(CURRENT_DNS, HashSet())!!)
+        currentDNS = deserializeStringSet2DNSInfoSet(
+            preferences.getStringSet(
+                CURRENT_DNS,
+                HashSet()
+            )!!
+        )
         val adapterDns = DNSInfoListAdapter(this, currentDNS.sortedWith(compareBy { it.ping }))
         listViewDNS.adapter = adapterDns
         val editDnsButton = findViewById<Button>(R.id.editDNS)
@@ -193,10 +201,12 @@ class MainActivity : AppCompatActivity() {
             val cl = classLoader
             val c: Class<*> = dexFile.loadClass("dummy/Dummy", cl)
         }
+        val versionName = findViewById<Button>(R.id.about)
+        versionName.text = """version: ${BuildConfig.VERSION_NAME} build:(${BuildConfig.VERSION_CODE})"""
     }
 
     private fun stopVpn(){
-        Log.i(TAG,"Stop")
+        Log.i(TAG, "Stop")
         val intent = Intent(this, YggdrasilTunService::class.java)
         val TASK_CODE = 100
         val pi = createPendingResult(TASK_CODE, intent, 0)
@@ -206,7 +216,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun startVpn(){
-        Log.i(TAG,"Start")
+        Log.i(TAG, "Start")
         val intent= VpnService.prepare(this)
         if (intent!=null){
             startActivityForResult(intent, VPN_REQUEST_CODE)
@@ -216,7 +226,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun updateDNS(){
-        Log.i(TAG,"Update DNS")
+        Log.i(TAG, "Update DNS")
         val intent = Intent(this, YggdrasilTunService::class.java)
         val TASK_CODE = 100
         val pi = createPendingResult(TASK_CODE, intent, 0)
@@ -227,7 +237,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun updatePeers(){
-        Log.d(TAG,"Update Peers")
+        Log.d(TAG, "Update Peers")
         val intent = Intent(this, YggdrasilTunService::class.java)
         val TASK_CODE = 100
         val pi = createPendingResult(TASK_CODE, intent, 0)
@@ -258,9 +268,13 @@ class MainActivity : AppCompatActivity() {
             val pi = createPendingResult(TASK_CODE, intent, 0)
             intent.putExtra(PARAM_PINTENT, pi)
             intent.putExtra(COMMAND, START)
-            intent.putStringArrayListExtra(CURRENT_PEERS, serializePeerInfoSet2StringList(currentPeers))
+            intent.putStringArrayListExtra(
+                CURRENT_PEERS, serializePeerInfoSet2StringList(
+                    currentPeers
+                )
+            )
             intent.putStringArrayListExtra(CURRENT_DNS, serializeDNSInfoSet2StringList(currentDNS))
-            intent.putExtra(STATIC_IP, findViewById<Switch>(R.id.staticIP).isChecked)
+            intent.putExtra(STATIC_IP, findViewById<SwitchCompat>(R.id.staticIP).isChecked)
 
             startService(intent)
         }
@@ -272,7 +286,10 @@ class MainActivity : AppCompatActivity() {
                 var currentPeers = data.extras!!.getStringArrayList(PEER_LIST)
                 /*WiFi Direct test. need peer empty list*/
                 this.currentPeers = deserializeStringList2PeerInfoSet(currentPeers)
-                val adapter = PeerInfoListAdapter(this, this.currentPeers.sortedWith(compareBy { it.ping }))
+                val adapter = PeerInfoListAdapter(
+                    this,
+                    this.currentPeers.sortedWith(compareBy { it.ping })
+                )
                 val listView = findViewById<ListView>(R.id.peers)
                 listView.adapter = adapter
 
@@ -297,7 +314,10 @@ class MainActivity : AppCompatActivity() {
             if(data!!.extras!=null){
                 var currentDNS = data.extras!!.getStringArrayList(DNS_LIST)
                 this.currentDNS = deserializeStringList2DNSInfoSet(currentDNS)
-                val adapter = DNSInfoListAdapter(this, this.currentDNS.sortedWith(compareBy { it.ping }))
+                val adapter = DNSInfoListAdapter(
+                    this,
+                    this.currentDNS.sortedWith(compareBy { it.ping })
+                )
                 val listView = findViewById<ListView>(R.id.dns)
                 listView.adapter = adapter
                 //save to shared preferences
@@ -313,7 +333,7 @@ class MainActivity : AppCompatActivity() {
         when (resultCode) {
             STATUS_START -> {
                 print("service started")
-                if(this.currentPeers.isEmpty()){
+                if (this.currentPeers.isEmpty()) {
                     checkPeers()
                 }
             }
@@ -329,8 +349,8 @@ class MainActivity : AppCompatActivity() {
                 val ipLayout = findViewById<LinearLayout>(R.id.ipLayout)
                 ipLayout.visibility = View.GONE
             }
-            STATUS_PEERS_UPDATE ->{
-                if(data!!.extras!=null) {
+            STATUS_PEERS_UPDATE -> {
+                if (data!!.extras != null) {
                     thread(start = true) {
                         val meshPeers = deserializePeerStringList2PeerInfoSet(
                             data.extras!!.getStringArrayList(MESH_PEERS)
@@ -338,7 +358,8 @@ class MainActivity : AppCompatActivity() {
                         val listView = findViewById<ListView>(R.id.peers)
                         val adapter = PeerInfoListAdapter(
                             this@MainActivity,
-                            meshPeers.filter { it.schema!="self" }.sortedWith(compareBy { it.ping })
+                            meshPeers.filter { it.schema != "self" }
+                                .sortedWith(compareBy { it.ping })
                         )
                         runOnUiThread {
                             listView.adapter = adapter
diff --git a/app/src/main/res/layout/activity_about.xml b/app/src/main/res/layout/activity_about.xml
new file mode 100644
index 0000000..d3fb767
--- /dev/null
+++ b/app/src/main/res/layout/activity_about.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:app="http://schemas.android.com/apk/res-auto"
+        xmlns:tools="http://schemas.android.com/tools"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        tools:context=".MainActivity"
+        android:background="@color/grey">
+    <ScrollView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent">
+        <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="match_parent">
+            <TextView
+                    android:id="@+id/about"
+                    android:layout_width="match_parent"
+                    android:layout_height="match_parent">
+            </TextView>
+        </LinearLayout>
+    </ScrollView>
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index b73ee8e..9ecca0b 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -30,7 +30,7 @@
                     app:popupTheme="@style/AppTheme.PopupOverlay"
                     android:layout_marginRight="240dp" />
 
-            <Switch
+            <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/staticIP"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
@@ -42,7 +42,7 @@
                     android:text="Static IP"
                     android:textColor="@color/white"/>
 
-            <Switch
+            <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/switchOn"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
diff --git a/app/src/main/res/layout/content_main.xml b/app/src/main/res/layout/content_main.xml
index 07a268d..62cdb80 100644
--- a/app/src/main/res/layout/content_main.xml
+++ b/app/src/main/res/layout/content_main.xml
@@ -152,5 +152,12 @@
                 app:layout_constraintTop_toTopOf="parent"/>
 
     </LinearLayout>
-
+    <Button
+            android:id="@+id/about"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:background="@android:color/transparent"
+            app:layout_constraintBottom_toBottomOf="parent"
+            android:text=""
+            android:textSize="12sp" />
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values-v21/styles.xml b/app/src/main/res/values-v21/styles.xml
index b208867..a9fb390 100644
--- a/app/src/main/res/values-v21/styles.xml
+++ b/app/src/main/res/values-v21/styles.xml
@@ -2,6 +2,6 @@
 <resources>
 
     <style name="SwitchTheme" parent="Theme.AppCompat.Light">
-        <item name="android:colorControlActivated">@color/green</item>
+        <item name="colorControlActivated">@color/green</item>
     </style>
 </resources>
\ No newline at end of file