diff --git a/css/default.css b/css/default.css
index 85737e23..2c3bfd22 100644
--- a/css/default.css
+++ b/css/default.css
@@ -553,7 +553,8 @@ div.dropdown-menu i {
     text-align: left;
 }
 
-#modal-settings .accordion-inner .form-inline .label-text {
+#modal-settings .accordion-inner .form-inline .label-text,
+#modal-settings .accordion-inner .control-label {
 	margin: 0 10px;
 }
 
diff --git a/js/core.js b/js/core.js
index 341aa648..0ec52f07 100644
--- a/js/core.js
+++ b/js/core.js
@@ -17,7 +17,7 @@ define([
 
     // Used for periodic tasks
     var intervalId = undefined;
-    var periodicCallbacks = [];
+    var periodicCallbacks = [extensionMgr.onPeriodicRun];
     core.addPeriodicCallback = function(callback) {
         periodicCallbacks.push(callback);
     };
diff --git a/js/extensionMgr.js b/js/extensionMgr.js
index 8ab92100..ed175b03 100644
--- a/js/extensionMgr.js
+++ b/js/extensionMgr.js
@@ -40,10 +40,12 @@ define([
     }
 
     // Return a function that calls every callbacks from extensions
-    function createHook(hookName) {
+    function createHook(hookName, noLog) {
         var callbackList = getExtensionCallbackList(hookName);
         return function() {
-            logger.log(hookName, arguments);
+            if(!noLog) {
+                logger.log(hookName, arguments);
+            }
             var callbackArguments = arguments;
             _.each(callbackList, function(callback) {
                 callback.apply(null, callbackArguments);
@@ -52,8 +54,8 @@ define([
     }
 
     // Add a Hook to the extensionMgr
-    function addHook(hookName) {
-        extensionMgr[hookName] = createHook(hookName);
+    function addHook(hookName, noLog) {
+        extensionMgr[hookName] = createHook(hookName, noLog);
     }
 
     // Set extension config
@@ -87,7 +89,8 @@ define([
     addHook("onMessage");
     addHook("onError");
     addHook("onOfflineChanged");
-    addHook("onAsyncRunning");
+    addHook("onAsyncRunning", true);
+    addHook("onPeriodicRun", true);
 
     // To access modules that are loaded after extensions
     addHook("onFileMgrCreated");
diff --git a/js/extensions/buttonSync.js b/js/extensions/buttonSync.js
index 86f1b64f..f0d623f3 100644
--- a/js/extensions/buttonSync.js
+++ b/js/extensions/buttonSync.js
@@ -1,13 +1,26 @@
 define([
     "jquery",
     "underscore",
+    "utils",
     "text!html/buttonSync.html",
-], function($, _, buttonSyncHTML) {
+    "text!html/buttonSyncSettingsBloc.html",
+], function($, _, utils, buttonSyncHTML, buttonSyncSettingsBlocHTML) {
 
     var buttonSync = {
         extensionId: "buttonSync",
         extensionName: 'Button "Synchronize"',
-        settingsBloc: '<p>Adds a "Synchronize documents" button in the navigation bar.</p>'
+        defaultConfig: {
+            syncPeriod: 180000
+        },
+        settingsBloc: buttonSyncSettingsBlocHTML
+    };
+
+    buttonSync.onLoadSettings = function() {
+        utils.setInputValue("#input-sync-period", buttonSync.config.syncPeriod);
+    };
+
+    buttonSync.onSaveSettings = function(newConfig, event) {
+        newConfig.syncPeriod = utils.getInputIntValue("#input-sync-period", undefined, 0);
     };
 
     var button = undefined;
@@ -32,10 +45,21 @@ define([
         synchronizer = synchronizerParameter;
     };
 
+    // Run sync periodically
+    var lastSync = 0;
+    buttonSync.onPeriodicRun = function() {
+        if(viewerMode === true || !buttonSync.config.syncPeriod || lastSync + buttonSync.config.syncPeriod > utils.currentTime) {
+            return;
+        }
+        if(synchronizer.sync() === true) {
+            lastSync = utils.currentTime;
+        }
+    };
+
     buttonSync.onCreateButton = function() {
         button = $(buttonSyncHTML).click(function() {
             if(!$(this).hasClass("disabled")) {
-                synchronizer.forceSync();
+                synchronizer.sync();
             }
         });
         return button;
diff --git a/js/extensions/googleAnalytics.js b/js/extensions/googleAnalytics.js
index 156df549..af1c17bb 100644
--- a/js/extensions/googleAnalytics.js
+++ b/js/extensions/googleAnalytics.js
@@ -31,48 +31,48 @@ define([
             // Collect informations about user settings
             _gaq.push([
                 '_trackEvent',
-                "settings",
+                "Settings",
                 'layoutOrientation',
                 "" + settings.layoutOrientation
             ]);
             _gaq.push([
                 '_trackEvent',
-                "settings",
+                "Settings",
                 'lazyRendering',
                 "" + settings.lazyRendering
             ]);
             _gaq.push([
                 '_trackEvent',
-                "settings",
+                "Settings",
                 'editorFontSize',
                 "" + settings.editorFontSize
             ]);
             // Check if user has removed back links
             _gaq.push([
                 '_trackEvent',
-                "settings",
-                'defaultContentBacklink',
+                "Settings",
+                'defaultContent backlink',
                 "" + settings.defaultContent.indexOf(MAIN_URL) >= 0
             ]);
             _gaq.push([
                 '_trackEvent',
-                "settings",
-                'commitMsgBacklink',
+                "Settings",
+                'commitMsg backlink',
                 "" + settings.commitMsg.indexOf(MAIN_URL) >= 0
             ]);
             // Check if user has changed sshProxy
             _gaq.push([
                 '_trackEvent',
-                "settings",
-                'sshProxyChanged',
+                "Settings",
+                'sshProxy changed',
                 "" + settings.sshProxy != SSH_PROXY_URL
             ]);
             // Check if extensions have been disabled
             _.each(settings.extensionSettings, function(config, extensionId) {
                 _gaq.push([
                     '_trackEvent',
-                    "extensions",
-                    extensionId + "Enabled",
+                    "Extensions",
+                    extensionId + " enabled",
                     "" + config.enabled
                 ]);
             });
@@ -97,25 +97,34 @@ define([
         init();
     };
 
-    var currentAction = "No action";
-    googleAnalytics.onSyncRunning = function() {
-        currentAction = "Sync";
+    var currentAction = "Unknown";
+    var startTime = 0;
+    googleAnalytics.onSyncRunning = function(isRunning) {
+        if(isRunning === true) {
+            currentAction = "Sync";
+            startTime = new Date().getTime();
+        }
     };
-    googleAnalytics.onPublishRunning = function() {
-        currentAction = "Publish";
+    googleAnalytics.onPublishRunning = function(isRunning) {
+        if(isRunning === true) {
+            currentAction = "Publish";
+            startTime = new Date().getTime();
+        }
     };
     googleAnalytics.onAsyncRunning = function(isRunning) {
         if(isRunning === false) {
-            currentAction = "No action";
+            currentAction = "Unknown";
         }
     };
 
-    // Log sync frequency
+    // Log sync time
     googleAnalytics.onSyncSuccess = function() {
+        var endTime = new Date().getTime();
         _gaq.push([
-            '_trackEvent',
+            '_trackTiming',
             'Sync',
-            'SyncSuccess'
+            'SyncTime',
+            endTime - startTime
         ]);
     };
     // Log import frequency and provider
@@ -128,7 +137,7 @@ define([
         _gaq.push([
             '_trackEvent',
             'Sync',
-            'SyncImportProvider',
+            'SyncImport provider',
             provider.providerId
         ]);
     };
@@ -142,22 +151,24 @@ define([
         _gaq.push([
             '_trackEvent',
             'Sync',
-            'SyncExportProvider',
+            'SyncExport provider',
             syncAttributes.provider.providerId
         ]);
     };
-    // Log publish frequency and provider
+    // Log publish time and provider
     googleAnalytics.onPublishSuccess = function(fileDesc) {
+        var endTime = new Date().getTime();
         _gaq.push([
-            '_trackEvent',
+            '_trackTiming',
             'Publish',
-            'PublishSuccess'
+            'PublishSuccess',
+            endTime - startTime
         ]);
         _.each(fileDesc.publishLocations, function(publishAttributes) {
             _gaq.push([
                 '_trackEvent',
                 'Publish',
-                'PublishSuccessProvider',
+                'PublishSuccess provider',
                 publishAttributes.provider.providerId
             ]);
         });
@@ -167,7 +178,7 @@ define([
         _gaq.push([
             '_trackEvent',
             'Publish',
-            'NewPublishProvider',
+            'NewPublish provider',
             publishAttributes.provider.providerId
         ]);
     };
diff --git a/js/extensions/toc.js b/js/extensions/toc.js
index 7ced2925..b1945563 100644
--- a/js/extensions/toc.js
+++ b/js/extensions/toc.js
@@ -7,7 +7,7 @@ define([
 
     var toc = {
         extensionId: "toc",
-        extensionName: "Table of content",
+        extensionName: "Table of Content",
         optional: true,
         defaultConfig: {
             marker: "\\[(TOC|toc)\\]"
diff --git a/js/extensions/workingIndicator.js b/js/extensions/workingIndicator.js
index 31acb065..48e68fac 100644
--- a/js/extensions/workingIndicator.js
+++ b/js/extensions/workingIndicator.js
@@ -5,7 +5,7 @@ define([
 
     var workingIndicator = {
         extensionId: "workingIndicator",
-        extensionName: "Working indicator",
+        extensionName: "Working Indicator",
         settingsBloc: '<p>Displays an animated image when a network operation is running.</p>'
     };
 
diff --git a/js/html/buttonSyncSettingsBloc.html b/js/html/buttonSyncSettingsBloc.html
new file mode 100644
index 00000000..9a78bdc8
--- /dev/null
+++ b/js/html/buttonSyncSettingsBloc.html
@@ -0,0 +1,10 @@
+<p>Adds a "Synchronize documents" button in the navigation bar.</p>
+<div class="form-horizontal">
+	<div class="control-group">
+		<label class="control-label" for="input-sync-period">Sync period (optional)</label>
+		<div class="controls">
+			<input type="text" id="input-sync-period"
+				class="input-mini"> <span class="help-inline">ms</span>
+		</div>
+	</div>
+</div>
\ No newline at end of file
diff --git a/js/synchronizer.js b/js/synchronizer.js
index a5d5c117..9d096204 100644
--- a/js/synchronizer.js
+++ b/js/synchronizer.js
@@ -41,12 +41,6 @@ define([
         });
     });
 
-    // Force the synchronization
-    synchronizer.forceSync = function() {
-        lastSync = 0;
-        synchronizer.sync();
-    };
-
     // Recursive function to upload a single file on multiple locations
     var uploadSyncAttributesList = [];
     var uploadContent = undefined;
@@ -154,16 +148,14 @@ define([
 
     // Main entry point for synchronization
     var syncRunning = false;
-    var lastSync = 0;
     synchronizer.sync = function() {
-        // If sync is already running or timeout is not reached or offline
-        if(syncRunning || lastSync + SYNC_PERIOD > utils.currentTime || core.isOffline) {
-            return;
+        // If sync is already running or offline
+        if(syncRunning || core.isOffline) {
+            return false;
         }
         syncRunning = true;
         extensionMgr.onSyncRunning(true);
         uploadCycle = true;
-        lastSync = utils.currentTime;
 
         function isError(error) {
             if(error !== undefined) {
@@ -187,11 +179,8 @@ define([
                 extensionMgr.onSyncSuccess();
             });
         });
+        return true;
     };
-    // Run sync function periodically
-    if(viewerMode === false) {
-        core.addPeriodicCallback(synchronizer.sync);
-    }
 
     // Initialize the export dialog
     function initExportDialog(provider) {