--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -518,16 +518,19 @@ pref("app.update.socket.maxErrors", 20);
 // field.
 pref("app.update.log", true);
 #else
 // Explicitly disable the shutdown watchdog.  It's enabled by default.
 // When the updater is disabled, we want to know about shutdown hangs.
 pref("shutdown.watchdog.timeoutSecs", -1);
 #endif
 
+// Check daily for apps updates.
+pref("webapps.update.interval", 86400);
+
 // Extensions preferences
 pref("extensions.update.enabled", false);
 pref("extensions.getAddons.cache.enabled", false);
 
 // Context Menu
 pref("ui.click_hold_context_menus", true);
 pref("ui.click_hold_context_menus.delay", 750);
 

--- a/b2g/chrome/content/settings.js
+++ b/b2g/chrome/content/settings.js
@@ -313,17 +313,17 @@ let AdbController = {
         this.debug("updateState: Waiting for all vars to be initialized");
       }
       return;
     }
 
     // Check if we have a remote debugging session going on. If so, we won't
     // disable adb even if the screen is locked.
     let isDebugging = Object.keys(DebuggerServer._connections).length > 0;
-    debug("isDebugging=" + isDebugging);
+    this.debug("isDebugging=" + isDebugging);
 
     let enableAdb = this.remoteDebuggerEnabled &&
       (!(this.lockEnabled && this.locked) || isDebugging);
 
     let useDisableAdbTimer = true;
     try {
       if (Services.prefs.getBoolPref("marionette.defaultPrefs.enabled")) {
         // Marionette is enabled. Marionette requires that adb be on (and also

--- a/b2g/chrome/content/shell.js
+++ b/b2g/chrome/content/shell.js
@@ -1130,16 +1130,19 @@ window.addEventListener('ContentStart', 
     } else if (e.detail.type == "delete-crash" && e.detail.crashID) {
       debugCrashReport("deleting crash at user request ", e.detail.crashID);
       shell.deleteCrash(e.detail.crashID);
     }
   });
 });
 
 window.addEventListener('ContentStart', function update_onContentStart() {
+  Cu.import('resource://gre/modules/WebappsUpdater.jsm');
+  WebappsUpdater.handleContentStart(shell);
+
   let promptCc = Cc["@mozilla.org/updates/update-prompt;1"];
   if (!promptCc) {
     return;
   }
 
   let updatePrompt = promptCc.createInstance(Ci.nsIUpdatePrompt);
   if (!updatePrompt) {
     return;

--- a/b2g/components/B2GComponents.manifest
+++ b/b2g/components/B2GComponents.manifest
@@ -68,8 +68,13 @@ contract @mozilla.org/recovery-service;1
 
 # B2GAboutRedirector
 component {920400b1-cf8f-4760-a9c4-441417b15134} B2GAboutRedirector.js
 contract @mozilla.org/network/protocol/about;1?what=certerror {920400b1-cf8f-4760-a9c4-441417b15134}
 
 # FilePicker.js
 component {436ff8f9-0acc-4b11-8ec7-e293efba3141} FilePicker.js
 contract @mozilla.org/filepicker;1 {436ff8f9-0acc-4b11-8ec7-e293efba3141}
+
+# WebappsUpdateTimer.js
+component {637b0f77-2429-49a0-915f-abf5d0db8b9a} WebappsUpdateTimer.js
+contract @mozilla.org/b2g/webapps-update-timer;1 {637b0f77-2429-49a0-915f-abf5d0db8b9a}
+category update-timer WebappsUpdateTimer @mozilla.org/b2g/webapps-update-timer;1,getService,background-update-timer,webapps.update.interval,86400

--- a/b2g/components/UpdatePrompt.js
+++ b/b2g/components/UpdatePrompt.js
@@ -7,16 +7,17 @@
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cu = Components.utils;
 const Cr = Components.results;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/WebappsUpdater.jsm");
 
 const VERBOSE = 1;
 let log =
   VERBOSE ?
   function log_dump(msg) { dump("UpdatePrompt: "+ msg +"\n"); } :
   function log_noop(msg) { };
 
 const PREF_APPLY_PROMPT_TIMEOUT          = "b2g.update.apply-prompt-timeout";
@@ -444,85 +445,30 @@ UpdatePrompt.prototype = {
         this.handleDownloadCancel();
         break;
       case "update-prompt-apply-result":
         this.handleApplyPromptResult(detail);
         break;
     }
   },
 
-  appsUpdated: function UP_appsUpdated(aApps) {
-    log("appsUpdated: " + aApps.length + " apps to update");
-    let lock = Services.settings.createLock();
-    lock.set("apps.updateStatus", "check-complete", null);
-    this.sendChromeEvent("apps-update-check", { apps: aApps });
-    this._checkingApps = false;
-  },
-
-  // Trigger apps update check and wait for all to be done before
-  // notifying gaia.
-  onUpdateCheckStart: function UP_onUpdateCheckStart() {
-    log("onUpdateCheckStart (" + this._checkingApps + ")");
-    // Don't start twice.
-    if (this._checkingApps) {
-      return;
-    }
-
-    this._checkingApps = true;
-
-    let self = this;
-
-    let window = Services.wm.getMostRecentWindow("navigator:browser");
-    let all = window.navigator.mozApps.mgmt.getAll();
-
-    all.onsuccess = function() {
-      let appsCount = this.result.length;
-      let appsChecked = 0;
-      let appsToUpdate = [];
-      this.result.forEach(function updateApp(aApp) {
-        let update = aApp.checkForUpdate();
-        update.onsuccess = function() {
-          if (aApp.downloadAvailable) {
-            appsToUpdate.push(aApp.manifestURL);
-          }
-
-          appsChecked += 1;
-          if (appsChecked == appsCount) {
-            self.appsUpdated(appsToUpdate);
-          }
-        }
-        update.onerror = function() {
-          appsChecked += 1;
-          if (appsChecked == appsCount) {
-            self.appsUpdated(appsToUpdate);
-          }
-        }
-      });
-    }
-
-    all.onerror = function() {
-      // Could not get the app list, just notify to update nothing.
-      self.appsUpdated([]);
-    }
-  },
-
   // nsIObserver
 
   observe: function UP_observe(aSubject, aTopic, aData) {
     switch (aTopic) {
       case "idle":
         this._waitingForIdle = false;
         this.showApplyPrompt(this._update);
         // Fall through
       case "quit-application":
         Services.idle.removeIdleObserver(this, this.applyIdleTimeout / 1000);
         Services.obs.removeObserver(this, "quit-application");
         break;
       case "update-check-start":
-        this.onUpdateCheckStart();
+        WebappsUpdater.updateApps();
         break;
     }
   },
 
   // nsITimerCallback
 
   notify: function UP_notify(aTimer) {
     if (aTimer == this._applyPromptTimer) {

new file mode 100644
--- /dev/null
+++ b/b2g/components/WebappsUpdateTimer.js
@@ -0,0 +1,67 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This component triggers an app update check even when system updates are
+ * disabled to make sure we always check for app updates.
+ */
+
+"use strict";
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/WebappsUpdater.jsm");
+
+function debug(aStr) {
+  //dump("--*-- WebappsUpdateTimer: " + aStr);
+}
+
+function WebappsUpdateTimer() {
+}
+
+WebappsUpdateTimer.prototype = {
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsITimerCallback]),
+  classID: Components.ID("{637b0f77-2429-49a0-915f-abf5d0db8b9a}"),
+
+  notify: function(aTimer) {
+    try {
+      // We want to check app updates if system updates are disabled or
+      // if they update frecency is not daily.
+      if (Services.prefs.getBoolPref("app.update.enabled") === true &&
+          Services.prefs.getIntPref("app.update.interval") === 86400) {
+        return;
+      }
+    } catch(e) {
+      // That should never happen..
+    }
+
+    // If we are offline, wait to be online to start the update check.
+    if (Services.io.offline) {
+      debug("Network is offline. Setting up an offline status observer.");
+      Services.obs.addObserver(this, "network:offline-status-changed", false);
+      return;
+    }
+
+    // This will trigger app updates in b2g/components/WebappsUpdater.jsm
+    // that also takes care of notifying gaia.
+    WebappsUpdater.updateApps();
+  },
+
+  observe: function(aSubject, aTopic, aData) {
+    if (aTopic !== "network:offline-status-changed" ||
+        aData !== "online") {
+      return;
+    }
+
+    debug("Network is online. Checking updates.");
+    Services.obs.removeObserver(this, "network:offline-status-changed");
+    WebappsUpdater.updateApps();
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([WebappsUpdateTimer]);

new file mode 100644
--- /dev/null
+++ b/b2g/components/WebappsUpdater.jsm
@@ -0,0 +1,95 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["WebappsUpdater"];
+
+const Cc = Components.classes;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm");
+
+this.WebappsUpdater = {
+  _checkingApps: false,
+  _pendingEvents: [],
+
+  handleContentStart: function(aShell) {
+    let content = aShell.contentBrowser.contentWindow;
+    this._pendingEvents.forEach(aShell.sendChromeEvent);
+
+    this._pendingEvents.length = 0;
+  },
+
+  sendChromeEvent: function(aType, aDetail) {
+    let detail = aDetail || {};
+    detail.type = aType;
+
+    let browser = Services.wm.getMostRecentWindow("navigator:browser");
+    if (!browser) {
+      this._pendingEvents.push(detail);
+      dump("Warning: Couldn't send update event " + aType +
+          ": no content browser. Will send again when content becomes available.");
+      return false;
+    }
+
+    browser.shell.sendChromeEvent(detail);
+    return true;
+  },
+
+  _appsUpdated: function(aApps) {
+    dump("appsUpdated: " + aApps.length + " apps to update");
+    let lock = Services.settings.createLock();
+    lock.set("apps.updateStatus", "check-complete", null);
+    this.sendChromeEvent("apps-update-check", { apps: aApps });
+    this._checkingApps = false;
+  },
+
+  // Trigger apps update check and wait for all to be done before
+  // notifying gaia.
+  updateApps: function() {
+    dump("updateApps (" + this._checkingApps + ")");
+    // Don't start twice.
+    if (this._checkingApps) {
+      return;
+    }
+
+    this._checkingApps = true;
+
+    let self = this;
+
+    let window = Services.wm.getMostRecentWindow("navigator:browser");
+    let all = window.navigator.mozApps.mgmt.getAll();
+
+    all.onsuccess = function() {
+      let appsCount = this.result.length;
+      let appsChecked = 0;
+      let appsToUpdate = [];
+      this.result.forEach(function updateApp(aApp) {
+        let update = aApp.checkForUpdate();
+        update.onsuccess = function() {
+          if (aApp.downloadAvailable) {
+            appsToUpdate.push(aApp.manifestURL);
+          }
+
+          appsChecked += 1;
+          if (appsChecked == appsCount) {
+            self._appsUpdated(appsToUpdate);
+          }
+        }
+        update.onerror = function() {
+          appsChecked += 1;
+          if (appsChecked == appsCount) {
+            self._appsUpdated(appsToUpdate);
+          }
+        }
+      });
+    }
+
+    all.onerror = function() {
+      // Could not get the app list, just notify to update nothing.
+      self._appsUpdated([]);
+    }
+  }
+};

--- a/b2g/components/moz.build
+++ b/b2g/components/moz.build
@@ -20,16 +20,17 @@ EXTRA_COMPONENTS += [
     'ContentPermissionPrompt.js',
     'FilePicker.js',
     'MailtoProtocolHandler.js',
     'MozKeyboard.js',
     'PaymentGlue.js',
     'ProcessGlobal.js',
     'SmsProtocolHandler.js',
     'TelProtocolHandler.js',
+    'WebappsUpdateTimer.js',
     'YoutubeProtocolHandler.js',
 ]
 
 EXTRA_PP_COMPONENTS += [
     'B2GComponents.manifest',
     'DirectoryProvider.js',
     'RecoveryService.js',
 ]
@@ -39,9 +40,10 @@ if CONFIG['MOZ_UPDATER']:
         'UpdatePrompt.js',
     ]
 
 EXTRA_JS_MODULES += [
     'ErrorPage.jsm',
     'Keyboard.jsm',
     'SignInToWebsite.jsm',
     'TelURIParser.jsm',
+    'WebappsUpdater.jsm',
 ]

--- a/b2g/installer/package-manifest.in
+++ b/b2g/installer/package-manifest.in
@@ -728,16 +728,17 @@ bin/components/@DLL_PREFIX@nkgnomevfs@DL
 @BINPATH@/components/MarionetteComponents.manifest
 @BINPATH@/components/marionettecomponent.js
 #endif
 @BINPATH@/components/AlertsService.js
 @BINPATH@/components/ContentPermissionPrompt.js
 #ifdef MOZ_UPDATER
 @BINPATH@/components/UpdatePrompt.js
 #endif
+@BINPATH@/components/WebappsUpdateTimer.js
 @BINPATH@/components/MozKeyboard.js
 @BINPATH@/components/DirectoryProvider.js
 @BINPATH@/components/ActivitiesGlue.js
 @BINPATH@/components/ProcessGlobal.js
 @BINPATH@/components/ContentHandler.js
 @BINPATH@/components/PaymentGlue.js
 @BINPATH@/components/YoutubeProtocolHandler.js
 @BINPATH@/components/RecoveryService.js