diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/APIUtil.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/APIUtil.java
index c9dfbb057ad..917c35bbf5b 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/APIUtil.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/APIUtil.java
@@ -37,7 +37,8 @@ public class APIUtil {
 
     private static ApplicationManager applicationManager;
 
-    public static ApplicationManager getApplicationManagemer() {
+    public static ApplicationManager getApplicationManager() {
+
         if (applicationManager == null) {
             synchronized (APIUtil.class) {
                 if (applicationManager == null) {
@@ -52,10 +53,12 @@ public class APIUtil {
                 }
             }
         }
+
         return applicationManager;
     }
 
     public static Response getResponse(ApplicationManagementException ex, Response.Status status) {
+
         //TODO: check for exception type and set the response code.
         ErrorResponse errorMessage = new ErrorResponse();
         errorMessage.setMessage(ex.getMessage());
@@ -64,5 +67,6 @@ public class APIUtil {
         }
         errorMessage.setCode(status.getStatusCode());
         return Response.status(status).entity(errorMessage).build();
+
     }
 }
diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/services/impl/ApplicationManagementAPIImpl.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/services/impl/ApplicationManagementAPIImpl.java
index 06e95af7b04..f45883c46e9 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/services/impl/ApplicationManagementAPIImpl.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/services/impl/ApplicationManagementAPIImpl.java
@@ -44,7 +44,7 @@ public class ApplicationManagementAPIImpl {
     @Path("applications")
     public Response getApplications(@QueryParam("offset") int offset, @QueryParam("limit") int limit,
                                     @QueryParam("query") String searchQuery) {
-        ApplicationManager applicationManager = APIUtil.getApplicationManagemer();
+        ApplicationManager applicationManager = APIUtil.getApplicationManager();
         try {
             if (limit == 0) {
                 limit = DEFAULT_LIMIT;
diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationManager.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationManager.java
index ae1752b8d8c..0642aef21cf 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationManager.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationManager.java
@@ -25,7 +25,11 @@ import org.wso2.carbon.device.application.mgt.common.exception.ApplicationManage
 
 public interface ApplicationManager{
 
-     void createApplication(Application application) throws ApplicationManagementException;
+     public Application createApplication(Application application) throws ApplicationManagementException;
 
-     ApplicationList getApplications(Filter filter) throws ApplicationManagementException;
+     public Application editApplication(int applicationId, Application application) throws ApplicationManagementException;
+
+     public void deleteApplication(int applicationId) throws ApplicationManagementException;
+
+     public ApplicationList getApplications(Filter filter) throws ApplicationManagementException;
 }
diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationReleaseManager.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationReleaseManager.java
index 00c5855b6d8..7760d6205e5 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationReleaseManager.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/ApplicationReleaseManager.java
@@ -18,5 +18,11 @@
  */
 package org.wso2.carbon.device.application.mgt.common.services;
 
+import org.wso2.carbon.device.application.mgt.common.Application;
+import org.wso2.carbon.device.application.mgt.common.ApplicationList;
+import org.wso2.carbon.device.application.mgt.common.Filter;
+import org.wso2.carbon.device.application.mgt.common.exception.ApplicationManagementException;
+
 public interface ApplicationReleaseManager{
+
 }
diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/CategoryManager.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/CategoryManager.java
index 47812996775..32082c865bb 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/CategoryManager.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/services/CategoryManager.java
@@ -18,5 +18,19 @@
  */
 package org.wso2.carbon.device.application.mgt.common.services;
 
+import org.wso2.carbon.device.application.mgt.common.Application;
+import org.wso2.carbon.device.application.mgt.common.ApplicationList;
+import org.wso2.carbon.device.application.mgt.common.Category;
+import org.wso2.carbon.device.application.mgt.common.Filter;
+import org.wso2.carbon.device.application.mgt.common.exception.ApplicationManagementException;
+
 public interface CategoryManager{
+
+    public Category createCategory(Category application) throws ApplicationManagementException;
+
+    public Category editCategory(int applicationId, Category category) throws ApplicationManagementException;
+
+    public void deleteCategory(int applicationId) throws ApplicationManagementException;
+
+    public Category getCategory(Filter filter) throws ApplicationManagementException;
 }
diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/ApplicationManagerImpl.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/ApplicationManagerImpl.java
index 5fbb970ae97..57cd962539d 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/ApplicationManagerImpl.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/ApplicationManagerImpl.java
@@ -29,13 +29,25 @@ import org.wso2.carbon.device.application.mgt.core.dao.common.DAOFactory;
 import org.wso2.carbon.device.application.mgt.core.util.ConnectionManagerUtil;
 
 public class ApplicationManagerImpl implements ApplicationManager {
+
     @Override
-    public void createApplication(Application application) throws ApplicationManagementException {
+    public Application createApplication(Application application) throws ApplicationManagementException {
+        return null;
+    }
+
+    @Override
+    public Application editApplication(int applicationId, Application application) throws ApplicationManagementException {
+        return null;
+    }
+
+    @Override
+    public void deleteApplication(int applicationId) throws ApplicationManagementException {
 
     }
 
     @Override
     public ApplicationList getApplications(Filter filter) throws ApplicationManagementException {
+
         try {
             ConnectionManagerUtil.openConnection();
             ApplicationDAO applicationDAO = DAOFactory.getApplicationDAO();
@@ -43,5 +55,6 @@ public class ApplicationManagerImpl implements ApplicationManager {
         }  finally {
             ConnectionManagerUtil.closeConnection();
         }
+
     }
 }
diff --git a/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/CategoryManagerImpl.java b/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/CategoryManagerImpl.java
index e245186b1a2..c165a58fc0e 100644
--- a/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/CategoryManagerImpl.java
+++ b/components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/impl/CategoryManagerImpl.java
@@ -17,7 +17,30 @@
 */
 package org.wso2.carbon.device.application.mgt.core.impl;
 
+import org.wso2.carbon.device.application.mgt.common.Category;
+import org.wso2.carbon.device.application.mgt.common.Filter;
+import org.wso2.carbon.device.application.mgt.common.exception.ApplicationManagementException;
 import org.wso2.carbon.device.application.mgt.common.services.CategoryManager;
 
 public class CategoryManagerImpl implements CategoryManager {
+
+    @Override
+    public Category createCategory(Category application) throws ApplicationManagementException {
+        return null;
+    }
+
+    @Override
+    public Category editCategory(int applicationId, Category category) throws ApplicationManagementException {
+        return null;
+    }
+
+    @Override
+    public void deleteCategory(int applicationId) throws ApplicationManagementException {
+
+    }
+
+    @Override
+    public Category getCategory(Filter filter) throws ApplicationManagementException {
+        return null;
+    }
 }