diff --git a/app/src/main/java/ch/pizzalink/android/activity/SplashActivity.java b/app/src/main/java/ch/pizzalink/android/activity/SplashActivity.java
index 7682c52..da17049 100644
--- a/app/src/main/java/ch/pizzalink/android/activity/SplashActivity.java
+++ b/app/src/main/java/ch/pizzalink/android/activity/SplashActivity.java
@@ -2,6 +2,8 @@ package ch.pizzalink.android.activity;
 
 import android.annotation.TargetApi;
 import android.content.Intent;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
@@ -11,9 +13,11 @@ import android.view.Window;
 import android.view.WindowManager;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 
 import butterknife.ButterKnife;
 import ch.pizzalink.android.R;
+import ch.pizzalink.android.api.ApiConstants;
 import ch.pizzalink.android.api.ApiErrorUtils;
 import ch.pizzalink.android.api.ApiService;
 import ch.pizzalink.android.api.ResponseArray;
@@ -23,6 +27,7 @@ import ch.pizzalink.android.helper.DisplayHelper;
 import ch.pizzalink.android.helper.NetworkHelper;
 import ch.pizzalink.android.helper.SessionHelper;
 import ch.pizzalink.android.helper.SharedPrefsHelper;
+import ch.pizzalink.android.model.AppVersionModel;
 import ch.pizzalink.android.model.CategoryModel;
 import ch.pizzalink.android.model.cart.CartInfoModel;
 import retrofit2.Call;
@@ -38,11 +43,54 @@ public class SplashActivity extends BaseActivity {
         ButterKnife.bind(this);
         //DisplayHelper.changeStatusColor();
         if(NetworkHelper.isNetworkAvailable())
-            getCategoryList();
+            checkVersion();
         else
             DialogHelper.showNoNetworkDialog();
     }
 
+    private void checkVersion(){
+        Call<ResponseObject<AppVersionModel>> call = ApiService.apiInterface.checkUpdate(getCheckUpdateParams());
+        call.enqueue(new Callback<ResponseObject<AppVersionModel>>() {
+            @Override
+            public void onResponse(Call<ResponseObject<AppVersionModel>> call, Response<ResponseObject<AppVersionModel>> response) {
+                if(response.isSuccessful()){
+                    if(response.body().isSuccess()){
+                        getCategoryList();
+                    }
+                    else{
+                        DialogHelper.showUpdateAppDialog(SplashActivity.this);
+                    }
+                }
+                else{
+                    ApiErrorUtils.parseError(response);
+                }
+            }
+
+            @Override
+            public void onFailure(Call<ResponseObject<AppVersionModel>> call, Throwable t) {
+                DialogHelper.showFailedDialog();
+            }
+        });
+    }
+
+    private HashMap<String, Object> getCheckUpdateParams(){
+        HashMap<String, Object> params = new HashMap<>();
+        params.put("application", ApiConstants.APP_TYPE_ID_ANDROID);
+        params.put("version", getAppVersionCode());
+        return params;
+    }
+
+    private int getAppVersionCode(){
+        PackageInfo pInfo = null;
+        try {
+            pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
+        } catch (PackageManager.NameNotFoundException e) {
+            e.printStackTrace();
+            return 0;
+        }
+        return pInfo.versionCode;
+    }
+
     private void getCategoryList(){
         Call<ResponseArray<CategoryModel>> call = ApiService.apiInterface.getAllCategories();
         call.enqueue(new Callback<ResponseArray<CategoryModel>>() {
@@ -66,6 +114,7 @@ public class SplashActivity extends BaseActivity {
         });
     }
 
+    /*
     private void checkCustomerToken(){
 
         if(SessionHelper.isCustomerLoggedIn()){
@@ -77,6 +126,16 @@ public class SplashActivity extends BaseActivity {
         else
             openActivity(LoginActivity.class);
     }
+    */
+
+    private void checkCustomerToken(){
+        if(SessionHelper.isCustomerLoggedIn()){
+            getCartItemCount();
+        }
+        else{
+            openActivity(LoginActivity.class);
+        }
+    }
 
     private void openActivity(final Class<?> cls){
         Handler handler = new Handler();
@@ -130,6 +189,7 @@ public class SplashActivity extends BaseActivity {
 
                 }
                 else
+                    //response.body().getErrorCode()
                     ApiErrorUtils.parseError(response);
             }
 
diff --git a/app/src/main/java/ch/pizzalink/android/api/ApiConstants.java b/app/src/main/java/ch/pizzalink/android/api/ApiConstants.java
index 6913c79..056a63a 100644
--- a/app/src/main/java/ch/pizzalink/android/api/ApiConstants.java
+++ b/app/src/main/java/ch/pizzalink/android/api/ApiConstants.java
@@ -8,4 +8,6 @@ public class ApiConstants {
     public static final int CATEGORY_ID_EKSTRA_KEBAP = 9998;
     public static final int PRODUCT_ID_WUNSCHPIZZA = 56;
     public static final int PRODUCT_ID_EKSTRA_KEBAP = 91;
+    public static final String APP_TYPE_ID_ANDROID = "2";
+    public static final int APP_ERROR_CODE_AUTHORIZATION = 1;
 }
diff --git a/app/src/main/java/ch/pizzalink/android/api/ApiEndPoints.java b/app/src/main/java/ch/pizzalink/android/api/ApiEndPoints.java
index b4298ed..16d3a73 100644
--- a/app/src/main/java/ch/pizzalink/android/api/ApiEndPoints.java
+++ b/app/src/main/java/ch/pizzalink/android/api/ApiEndPoints.java
@@ -19,6 +19,7 @@ public class ApiEndPoints {
     public static final String API_GET_CUSTOMER_ADDRESSES = PREFIX + "getAddresses" + SUFFIX;
     public static final String API_GET_PAYMENT_METHODS = PREFIX + "getPaymentMethodsArray" + SUFFIX;
     public static final String API_CREATE_ORDER = PREFIX + "addOrder" + SUFFIX + "&token=";
+    public static final String API_CHECK_UPDATE = PREFIX + "checkUpdate" + SUFFIX;
 
 
 }
diff --git a/app/src/main/java/ch/pizzalink/android/api/ApiErrorUtils.java b/app/src/main/java/ch/pizzalink/android/api/ApiErrorUtils.java
index fc39f8c..e3d9f75 100644
--- a/app/src/main/java/ch/pizzalink/android/api/ApiErrorUtils.java
+++ b/app/src/main/java/ch/pizzalink/android/api/ApiErrorUtils.java
@@ -1,11 +1,15 @@
 package ch.pizzalink.android.api;
 
+import android.content.Intent;
+
 import java.io.IOException;
 import java.lang.annotation.Annotation;
 
 import ch.pizzalink.android.R;
 import ch.pizzalink.android.activity.BaseActivity;
+import ch.pizzalink.android.activity.LoginActivity;
 import ch.pizzalink.android.helper.DialogHelper;
+import ch.pizzalink.android.helper.SharedPrefsHelper;
 import okhttp3.ResponseBody;
 import retrofit2.Converter;
 import retrofit2.Response;
@@ -15,6 +19,18 @@ public class ApiErrorUtils {
         Converter<ResponseBody, ApiError> converter = ApiService.retrofit.responseBodyConverter(ApiError.class, new Annotation[0]);
         ApiError error = new ApiError();
         error.setStatusCode(response.code());
+
+        BaseResponse baseResponse = (BaseResponse) response.body();
+
+        if(baseResponse.getErrorCode() == ApiConstants.APP_ERROR_CODE_AUTHORIZATION){
+            SharedPrefsHelper.clearCustomerInfo();
+            SharedPrefsHelper.clearCustomerToken();
+            SharedPrefsHelper.setCustomerLoggedIn(false);
+            BaseActivity.currentActivity.startActivity(new Intent(BaseActivity.currentActivity, LoginActivity.class));
+            BaseActivity.currentActivity.finishAffinity();
+            return error;
+        }
+
         try {
             error = converter.convert(response.errorBody());
             DialogHelper.showDialogWithPositiveButton(BaseActivity.currentActivity, error.getMessage());
diff --git a/app/src/main/java/ch/pizzalink/android/api/ApiInterface.java b/app/src/main/java/ch/pizzalink/android/api/ApiInterface.java
index ad32447..b50b16c 100644
--- a/app/src/main/java/ch/pizzalink/android/api/ApiInterface.java
+++ b/app/src/main/java/ch/pizzalink/android/api/ApiInterface.java
@@ -4,6 +4,7 @@ import java.util.HashMap;
 
 import ch.pizzalink.android.model.AddProductToBasketResponseModel;
 import ch.pizzalink.android.model.AddressModel;
+import ch.pizzalink.android.model.AppVersionModel;
 import ch.pizzalink.android.model.PaymentMethodModel;
 import ch.pizzalink.android.model.PaymentMethodsResponseModel;
 import ch.pizzalink.android.model.ShippingMethodModel;
@@ -95,4 +96,9 @@ public interface ApiInterface {
     @POST
     Call<ResponseObject<Integer>> createOrder(@Url String url, @FieldMap HashMap<String, Object> body);
 
+    @FormUrlEncoded
+    @POST(ApiEndPoints.API_CHECK_UPDATE)
+    Call<ResponseObject<AppVersionModel>> checkUpdate(@FieldMap HashMap<String, Object> body);
+
+
 }
diff --git a/app/src/main/java/ch/pizzalink/android/api/BaseResponse.java b/app/src/main/java/ch/pizzalink/android/api/BaseResponse.java
new file mode 100644
index 0000000..fe9ef98
--- /dev/null
+++ b/app/src/main/java/ch/pizzalink/android/api/BaseResponse.java
@@ -0,0 +1,28 @@
+package ch.pizzalink.android.api;
+
+import com.google.gson.annotations.SerializedName;
+
+import java.io.Serializable;
+
+/**
+ * Created by cimenmus on 22.10.2017.
+ */
+
+public class BaseResponse implements Serializable {
+
+    @SerializedName("success") private boolean success;
+    @SerializedName("message") private String message;
+    @SerializedName("error_code") private int errorCode;
+
+    public boolean isSuccess() {
+        return success;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public int getErrorCode() {
+        return errorCode;
+    }
+}
diff --git a/app/src/main/java/ch/pizzalink/android/api/ResponseArray.java b/app/src/main/java/ch/pizzalink/android/api/ResponseArray.java
index 77454b3..4169a2f 100644
--- a/app/src/main/java/ch/pizzalink/android/api/ResponseArray.java
+++ b/app/src/main/java/ch/pizzalink/android/api/ResponseArray.java
@@ -10,20 +10,10 @@ import java.util.List;
  * Created by cimenmus on 05/10/2017.
  */
 
-public class ResponseArray<T> implements Serializable {
+public class ResponseArray<T> extends BaseResponse implements Serializable {
 
-    @SerializedName("success") private boolean success;
-    @SerializedName("message") private String message;
     @SerializedName("data") private ArrayList<T> data;
 
-    public boolean isSuccess() {
-        return success;
-    }
-
-    public String getMessage() {
-        return message;
-    }
-
     public ArrayList<T> getData() {
         return data;
     }
diff --git a/app/src/main/java/ch/pizzalink/android/api/ResponseObject.java b/app/src/main/java/ch/pizzalink/android/api/ResponseObject.java
index 0f93a3b..0fd4397 100644
--- a/app/src/main/java/ch/pizzalink/android/api/ResponseObject.java
+++ b/app/src/main/java/ch/pizzalink/android/api/ResponseObject.java
@@ -8,20 +8,10 @@ import java.io.Serializable;
  * Created by cimenmus on 05/10/2017.
  */
 
-public class ResponseObject<T> implements Serializable {
+public class ResponseObject<T> extends BaseResponse implements Serializable {
 
-    @SerializedName("success") private boolean success;
-    @SerializedName("message") private String message;
     @SerializedName("data") private T data;
 
-    public boolean isSuccess() {
-        return success;
-    }
-
-    public String getMessage() {
-        return message;
-    }
-
     public T getData() {
         return data;
     }
diff --git a/app/src/main/java/ch/pizzalink/android/helper/DialogHelper.java b/app/src/main/java/ch/pizzalink/android/helper/DialogHelper.java
index 69764c4..332f9ee 100644
--- a/app/src/main/java/ch/pizzalink/android/helper/DialogHelper.java
+++ b/app/src/main/java/ch/pizzalink/android/helper/DialogHelper.java
@@ -1,6 +1,8 @@
 package ch.pizzalink.android.helper;
 
 import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
 import android.support.annotation.NonNull;
 import android.support.v4.content.ContextCompat;
 import com.afollestad.materialdialogs.DialogAction;
@@ -69,6 +71,12 @@ public class DialogHelper {
                 .content(BaseActivity.currentActivity.getString(R.string.no_network_message))
                 .positiveText(R.string.ok)
                 .positiveColor(ContextCompat.getColor(BaseActivity.currentActivity, R.color.colorPrimary))
+                .onPositive(new MaterialDialog.SingleButtonCallback() {
+                    @Override
+                    public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {
+                        BaseActivity.currentActivity.finishAffinity();
+                    }
+                })
                 .show();
     }
 
@@ -103,4 +111,25 @@ public class DialogHelper {
                 .show();
     }
 
+    public static void showUpdateAppDialog(Context context) {
+
+        new MaterialDialog.Builder(context)
+                .title(R.string.alert)
+                .content(R.string.alert_update_app)
+                .positiveText(R.string.update_app)
+                .positiveColor(ContextCompat.getColor(context, R.color.colorPrimary))
+                .cancelable(false)
+                .onPositive(new MaterialDialog.SingleButtonCallback() {
+                    @Override
+                    public void onClick(@NonNull MaterialDialog dialog, @NonNull DialogAction which) {
+                        Intent intent = new Intent(Intent.ACTION_VIEW);
+                        intent.setData(Uri.parse("market://details?id=ch.pizzalink.android"));
+                        BaseActivity.currentActivity.startActivity(intent);
+                        BaseActivity.currentActivity.finishAffinity();
+                    }
+                })
+                .show();
+
+    }
+
 }
diff --git a/app/src/main/java/ch/pizzalink/android/model/AppVersionModel.java b/app/src/main/java/ch/pizzalink/android/model/AppVersionModel.java
new file mode 100644
index 0000000..5c10998
--- /dev/null
+++ b/app/src/main/java/ch/pizzalink/android/model/AppVersionModel.java
@@ -0,0 +1,33 @@
+package ch.pizzalink.android.model;
+
+import com.google.gson.annotations.Expose;
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * Created by cimenmus on 22.10.2017.
+ */
+
+public class AppVersionModel {
+
+    @Expose
+    @SerializedName("application")
+    private String appType;
+
+    private int version;
+
+    public String getAppType() {
+        return appType;
+    }
+
+    public void setAppType(String appType) {
+        this.appType = appType;
+    }
+
+    public int getVersion() {
+        return version;
+    }
+
+    public void setVersion(int version) {
+        this.version = version;
+    }
+}
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index b95cb90..a9df2e6 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -99,6 +99,8 @@
     <string name="cancel">İptal</string>
     <string name="loading">Lütfen bekleyiniz...</string>
     <string name="alert_logout">Çıkış yapmak istediğinize emin misiniz?</string>
+    <string name="alert_update_app">Pizzalink uygulamasını kullanabilmek için uygulamanızı güncellemeniz gerekmektedir.</string>
+    <string name="update_app">GÜNCELLE</string>
 
     <string name="month_name_january">Jan.</string>
     <string name="month_name_february">Feb.</string>