Commented the example code.

flux/src/main/java/com/iluwatar/action/Action.java

@@ -1,6 +1,10 @@
 package com.iluwatar.action;
 
-
+/**
+ * 
+ * Action is the data payload dispatched to the stores when something happens.
+ *
+ */
 public abstract class Action {
 
 	private ActionType type;

flux/src/main/java/com/iluwatar/action/ActionType.java

@@ -1,5 +1,10 @@
 package com.iluwatar.action;
 
+/**
+ * 
+ * Types of actions.
+ *
+ */
 public enum ActionType {
 
 	MENU_ITEM_SELECTED, CONTENT_CHANGED;

flux/src/main/java/com/iluwatar/action/Content.java

@@ -1,5 +1,10 @@
 package com.iluwatar.action;
 
+/**
+ * 
+ * Content items.
+ *
+ */
 public enum Content {
 	
 	PRODUCTS("Products - This page lists the company's products."), COMPANY("Company - This page displays information about the company.");

flux/src/main/java/com/iluwatar/action/ContentAction.java

@@ -1,6 +1,10 @@
 package com.iluwatar.action;
 
-
+/**
+ * 
+ * ContentAction is a concrete action.
+ *
+ */
 public class ContentAction extends Action {
 
 	private Content content;

flux/src/main/java/com/iluwatar/action/MenuAction.java

@@ -1,6 +1,11 @@
 package com.iluwatar.action;
 
 
+/**
+ * 
+ * MenuAction is a concrete action.
+ *
+ */
 public class MenuAction extends Action {
 
 	private MenuItem menuItem;

flux/src/main/java/com/iluwatar/action/MenuItem.java

@@ -1,5 +1,10 @@
 package com.iluwatar.action;
 
+/**
+ * 
+ * Menu items.
+ *
+ */
 public enum MenuItem {
 	
 	HOME("Home"), PRODUCTS("Products"), COMPANY("Company");

flux/src/main/java/com/iluwatar/app/App.java

@@ -7,10 +7,25 @@ import com.iluwatar.store.MenuStore;
 import com.iluwatar.view.ContentView;
 import com.iluwatar.view.MenuView;
 
+/**
+ * 
+ * Flux is the application architecture that Facebook uses for building client-side web 
+ * applications. Flux eschews MVC in favor of a unidirectional data flow. When a user interacts with 
+ * a React view, the view propagates an action through a central dispatcher, to the various stores that 
+ * hold the application's data and business logic, which updates all of the views that are affected.  
+ * 
+ * This example has two views: menu and content. They represent typical main menu and content area of
+ * a web page. When menu item is clicked it triggers events through the dispatcher. The events are
+ * received and handled by the stores updating their data as needed. The stores then notify the views
+ * that they should rerender themselves.
+ * 
+ * http://facebook.github.io/flux/docs/overview.html
+ *
+ */
 public class App {
 	
     public static void main( String[] args ) {
-    	// initialize
+    	// initialize and wire the system
     	MenuStore menuStore = new MenuStore();
     	Dispatcher.getInstance().registerStore(menuStore);
     	ContentStore contentStore = new ContentStore();

flux/src/main/java/com/iluwatar/dispatcher/Dispatcher.java

@@ -10,6 +10,11 @@ import com.iluwatar.action.MenuAction;
 import com.iluwatar.action.MenuItem;
 import com.iluwatar.store.Store;
 
+/**
+ * 
+ * Dispatcher sends Actions to registered Stores.
+ *
+ */
 public class Dispatcher {
 	
 	private static Dispatcher instance = new Dispatcher();

flux/src/main/java/com/iluwatar/store/ContentStore.java

@@ -5,6 +5,11 @@ import com.iluwatar.action.ActionType;
 import com.iluwatar.action.Content;
 import com.iluwatar.action.ContentAction;
 
+/**
+ * 
+ * ContentStore is a concrete store.
+ *
+ */
 public class ContentStore extends Store {
 
 	private Content content = Content.PRODUCTS;

flux/src/main/java/com/iluwatar/store/MenuStore.java

@@ -5,6 +5,11 @@ import com.iluwatar.action.ActionType;
 import com.iluwatar.action.MenuAction;
 import com.iluwatar.action.MenuItem;
 
+/**
+ * 
+ * MenuStore is a concrete store.
+ *
+ */
 public class MenuStore extends Store {
 
 	private MenuItem selected = MenuItem.HOME;

flux/src/main/java/com/iluwatar/store/Store.java

@@ -6,6 +6,11 @@ import java.util.List;
 import com.iluwatar.action.Action;
 import com.iluwatar.view.View;
 
+/**
+ * 
+ * Store is a data model.
+ *
+ */
 public abstract class Store {
 	
 	private List<View> views = new LinkedList<>();

flux/src/main/java/com/iluwatar/view/ContentView.java

@@ -4,6 +4,11 @@ import com.iluwatar.action.Content;
 import com.iluwatar.store.ContentStore;
 import com.iluwatar.store.Store;
 
+/**
+ * 
+ * ContentView is a concrete view.
+ *
+ */
 public class ContentView implements View {
 
 	private Content content = Content.PRODUCTS;

flux/src/main/java/com/iluwatar/view/MenuView.java

@@ -5,6 +5,11 @@ import com.iluwatar.dispatcher.Dispatcher;
 import com.iluwatar.store.MenuStore;
 import com.iluwatar.store.Store;
 
+/**
+ * 
+ * MenuView is a concrete view.
+ *
+ */
 public class MenuView implements View {
 
 	private MenuItem selected = MenuItem.HOME;

flux/src/main/java/com/iluwatar/view/View.java

@@ -2,6 +2,11 @@ package com.iluwatar.view;
 
 import com.iluwatar.store.Store;
 
+/**
+ * 
+ * Views define the representation of data.
+ *
+ */
 public interface View {
 
 	public void storeChanged(Store store);