diff --git a/lib/js/kopi/app.js b/lib/js/kopi/app.js
index 6a87511..ce88f23 100644
--- a/lib/js/kopi/app.js
+++ b/lib/js/kopi/app.js
@@ -3,7 +3,7 @@
     __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };
 
   define("kopi/app", function(require, exports, module) {
-    var $, App, appInstance, array, baseURL, events, hist, klass, loc, logger, logging, overlays, settings, support, text, uri, utils, viewport, win;
+    var $, App, array, baseURL, events, hist, klass, loc, logger, logging, overlays, settings, support, text, uri, utils, viewport, win;
 
     $ = require("jquery");
     settings = require("kopi/settings");
@@ -22,7 +22,6 @@
     loc = location;
     baseURL = uri.current();
     logger = logging.logger(module.id);
-    appInstance = null;
     /*
     Application class
     
@@ -63,6 +62,8 @@
 
       App.UNLOCK_EVENT = "unlock";
 
+      klass.singleton(App);
+
       klass.configure(App);
 
       klass.accessor(App.prototype, "router");
@@ -73,10 +74,7 @@
         if (options == null) {
           options = {};
         }
-        if (appInstance) {
-          throw new Error("Only one app can be initialized in current page");
-        }
-        appInstance = this;
+        this._isSingleton();
         self = this;
         self.guid = utils.guid("app");
         self.started = false;
@@ -134,7 +132,7 @@
         cls = this.constructor;
         self = this;
         if (self.started) {
-          logger.warn("App has already been launched.");
+          logger.warn("[app:start] App has already been launched.");
           return self;
         }
         self.container = $("body");
@@ -142,7 +140,7 @@
         self.viewport.skeleton().render();
         self._listenToURLChange();
         self.emit(cls.START_EVENT);
-        logger.info("Start app: " + self.guid);
+        logger.info("[app:start] Start app: " + self.guid);
         self.started = true;
         if (!(support.history && self._options.usePushState)) {
           self.load(self._options.startURL || self.getCurrentURL());
@@ -156,7 +154,6 @@
         self = this;
         self._stopListenToURLChange();
         self.started = false;
-        appInstance = null;
         return self;
       };
 
@@ -178,7 +175,7 @@
       App.prototype.load = function(url, options) {
         var cls, self, state;
 
-        logger.info("Load URL: " + url);
+        logger.info("[app:load] Load URL: " + url);
         cls = this.constructor;
         self = this;
         url = uri.parse(uri.absolute(url));
@@ -211,15 +208,15 @@
       App.prototype.onrequest = function(e, url, options) {
         var cls, isUpdate, match, request, self, view;
 
-        logger.info("Receive request: " + url.path);
+        logger.info("[app:onrequest] Receive request: " + url.path);
         self = this;
         cls = this.constructor;
         match = self._match(url);
         if (!match) {
-          logger.info("No matching view found.");
+          logger.info("[app:onrequest] No matching view found.");
           if (self._options.redirectWhenNoRouteFound) {
             url = uri.unparse(url);
-            logger.info("Redirect to URL: " + url);
+            logger.info("[app:onrequest] Redirect to URL: " + url);
             uri.goto(url);
           }
           return;
@@ -268,7 +265,7 @@
           self._useHash = true;
           self._interval = setInterval(checkFn, self._options.interval);
         } else {
-          logger.warn("App will not repond to url change");
+          logger.warn("[app:_listenToURLChange] App will not repond to url change");
         }
       };
 
@@ -329,19 +326,20 @@
         var guid, matches, param, path, request, route, self, view, _i, _len, _ref, _ref1;
 
         if (!this._router) {
-          return logger.warn("Router is not provided");
+          return logger.warn("[app:_match] Router is not provided");
         }
         self = this;
         path = uri.parse(url).path;
         request = this._router.match(path);
         if (!request) {
-          return logger.warn("Can not find proper route for path: " + path);
+          return logger.warn("[app:_match] Can not find proper route for path: " + path);
         }
         route = request.route;
         _ref = self._views;
         for (guid in _ref) {
           view = _ref[guid];
-          if (route.group === true && view.name === route.view.name) {
+          if (route.group === true && view.constructor.viewName() === route.view.viewName()) {
+            logger.log("[app:_match] group: true");
             return [view, request];
           } else if (text.isString(route.group)) {
             if (view.params[route.group] === route.params[route.group]) {
@@ -377,7 +375,7 @@
     return {
       App: App,
       instance: function() {
-        return appInstance;
+        return App.instance();
       }
     };
   });
diff --git a/lib/js/kopi/utils/klass.js b/lib/js/kopi/utils/klass.js
index ce9a037..86ae08e 100644
--- a/lib/js/kopi/utils/klass.js
+++ b/lib/js/kopi/utils/klass.js
@@ -4,6 +4,7 @@
 
   define("kopi/utils/klass", function(require, exports, module) {
     var SingletonError, accessor, configure, create, include, object, reader, singleton;
+
     object = require("kopi/utils/object");
     SingletonError = require("kopi/exceptions").SingletonError;
     /*
@@ -16,6 +17,7 @@
 
     create = function(name, parent) {
       var ctor, key, klass, value;
+
       if (parent) {
         klass = function() {
           return parent.constructor.apply(this, arguments);
@@ -47,6 +49,7 @@
 
     include = function(klass, mixin) {
       var method, name, _ref;
+
       for (name in mixin) {
         if (!__hasProp.call(mixin, name)) continue;
         method = mixin[name];
@@ -64,6 +67,7 @@
     };
     configure = function(klass, options) {
       var _base;
+
       klass._options || (klass._options = {});
       if (options) {
         klass._options = object.extend({}, klass._options, options);
@@ -92,6 +96,7 @@
 
     accessor = function(klass, method, property) {
       var name;
+
       if (property == null) {
         property = {};
       }
@@ -132,6 +137,7 @@
 
     reader = function(klass, method, property) {
       var name;
+
       if (property == null) {
         property = {};
       }
@@ -158,6 +164,7 @@
 
     singleton = function(klass) {
       var instance;
+
       instance = null;
       klass.instance = function() {
         return instance;
diff --git a/src/coffee/kopi/app.coffee b/src/coffee/kopi/app.coffee
index e36d2f4..9fb5acf 100644
--- a/src/coffee/kopi/app.coffee
+++ b/src/coffee/kopi/app.coffee
@@ -18,7 +18,6 @@ define "kopi/app", (require, exports, module) ->
   loc = location
   baseURL = uri.current()
   logger = logging.logger(module.id)
-  appInstance = null
 
   ###
   Application class
@@ -55,15 +54,14 @@ define "kopi/app", (require, exports, module) ->
     @LOCK_EVENT = "lock"
     @UNLOCK_EVENT = "unlock"
 
+    klass.singleton this
+
     klass.configure this
 
     klass.accessor @prototype, "router"
 
     constructor: (options={}) ->
-      # Make sure only one app is launched in current page
-      throw new Error("Only one app can be initialized in current page") if appInstance
-      # Set singleton of application
-      appInstance = this
+      @_isSingleton()
 
       self = this
       self.guid = utils.guid("app")
@@ -107,7 +105,7 @@ define "kopi/app", (require, exports, module) ->
       cls = this.constructor
       self = this
       if self.started
-        logger.warn("App has already been launched.")
+        logger.warn("[app:start] App has already been launched.")
         return self
       # Ensure layout elements
       self.container = $("body")
@@ -115,7 +113,7 @@ define "kopi/app", (require, exports, module) ->
       self.viewport.skeleton().render()
       self._listenToURLChange()
       self.emit(cls.START_EVENT)
-      logger.info "Start app: #{self.guid}"
+      logger.info "[app:start] Start app: #{self.guid}"
       self.started = true
       # Load current URL
       unless support.history and self._options.usePushState
@@ -126,7 +124,6 @@ define "kopi/app", (require, exports, module) ->
       self = this
       self._stopListenToURLChange()
       self.started = false
-      appInstance = null
       self
 
     getCurrentURL: ->
@@ -140,7 +137,7 @@ define "kopi/app", (require, exports, module) ->
     @param {Hash} options
     ###
     load: (url, options) ->
-      logger.info "Load URL: #{url}"
+      logger.info "[app:load] Load URL: #{url}"
       cls = this.constructor
       self = this
       url = uri.parse uri.absolute(url)
@@ -169,16 +166,16 @@ define "kopi/app", (require, exports, module) ->
     @param {kopi.utils.uri.URI} url
     ###
     onrequest: (e, url, options) ->
-      logger.info "Receive request: #{url.path}"
+      logger.info "[app:onrequest] Receive request: #{url.path}"
       self = this
       cls = this.constructor
       match = self._match(url)
 
       if not match
-        logger.info "No matching view found."
+        logger.info "[app:onrequest] No matching view found."
         if self._options.redirectWhenNoRouteFound
           url = uri.unparse url
-          logger.info("Redirect to URL: #{url}")
+          logger.info("[app:onrequest] Redirect to URL: #{url}")
           uri.goto url
         return
 
@@ -224,7 +221,7 @@ define "kopi/app", (require, exports, module) ->
         self._useHash = true
         self._interval = setInterval checkFn, self._options.interval
       else
-        logger.warn("App will not repond to url change")
+        logger.warn("[app:_listenToURLChange] App will not repond to url change")
       return
 
     ###
@@ -269,20 +266,21 @@ define "kopi/app", (require, exports, module) ->
     @return {kopi.views.View}
     ###
     _match: (url) ->
-      return logger.warn "Router is not provided" unless @_router
+      return logger.warn "[app:_match] Router is not provided" unless @_router
 
       self = this
       path = uri.parse(url).path
       request = @_router.match(path)
 
       # If no proper router is found
-      return logger.warn("Can not find proper route for path: #{path}") unless request
+      return logger.warn("[app:_match] Can not find proper route for path: #{path}") unless request
 
       route = request.route
       for guid, view of self._views
         # If `group` is `true`, use same view for every URL matches route
-        if route.group is true and view.name == route.view.name
-            return [view, request]
+        if route.group is true and view.constructor.viewName() == route.view.viewName()
+          logger.log "[app:_match] group: true"
+          return [view, request]
         # If `group` is `string`, use same view for every URL matches route
         else if text.isString(route.group)
           if view.params[route.group] == route.params[route.group]
@@ -307,4 +305,7 @@ define "kopi/app", (require, exports, module) ->
       [view, request]
 
   App: App
-  instance: -> appInstance
+  # DEPRECATED
+  # Use App.instance() instead
+  # -- Wu Yuntao, 2013-07-01
+  instance: -> App.instance()
diff --git a/src/coffee/kopi/utils/klass.coffee b/src/coffee/kopi/utils/klass.coffee
index c7a0dfa..9d19b7f 100644
--- a/src/coffee/kopi/utils/klass.coffee
+++ b/src/coffee/kopi/utils/klass.coffee
@@ -112,8 +112,12 @@ define "kopi/utils/klass", (require, exports, module) ->
   ###
   singleton = (klass) ->
     instance = null
+    # Class method to get singleton
     klass.instance = -> instance
+    # Class method to remove singleton
     klass.removeInstance = -> instance = null
+    # A private instance method to check if instance
+    # can be initialized as a singleton
     klass.prototype._isSingleton = ->
       throw new SingletonError(klass) if instance
       instance = this