--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -1946,41 +1946,27 @@ var UserAgent = {
       }
       case "http-on-modify-request": {
         let channel = aSubject.QueryInterface(Ci.nsIHttpChannel);
         let channelWindow = this._getWindowForRequest(channel);
         let tab = BrowserApp.getTabForWindow(channelWindow);
         if (tab == null)
           break;
 
-        let apps = HelperApps.getAppsForUri(channel.URI);
-        if (apps.length > 0) {
-          let message = apps.length == 1 ? Strings.browser.formatStringFromName("helperapps.openWithApp", [apps[0].name], 1) :
-                                           Strings.browser.GetStringFromName("helperapps.openWithList");
-          let buttons = [{
-              label: Strings.browser.GetStringFromName("helperapps.open"),
-              callback: function() {
-                aSubject.QueryInterface(Ci.nsIRequest).cancel(Components.results.NS_ERROR_ABORT);
-                HelperApps.openUriInApp(channel.URI);
-              }
-            },
-            {
-              label: Strings.browser.GetStringFromName("helperapps.cancel"),
-              callback: function() { }
-          }];
-          // Persist this over page loads. Pages that expect to open in helper apps often redirect
-          // Youtube redirects twice, so I've forced this to two for now
-          let options = { persistence: 2 };
-          let name = "helperapps-" + (apps.length > 1 ? "list" : apps[0].name);
-          NativeWindow.doorhanger.show(message, name, buttons, self.id, options);
+        if (channel.URI.host.indexOf("youtube") != -1) {
+          let ua = Cc["@mozilla.org/network/protocol;1?name=http"].getService(Ci.nsIHttpProtocolHandler).userAgent;
+#expand let version = "__MOZ_APP_VERSION__";
+          ua += " Fennec/" + version;
+          channel.setRequestHeader("User-Agent", ua, false);
         }
 
         // Send desktop UA if "Request Desktop Site" is enabled
         if (tab.desktopMode && (channel.loadFlags & Ci.nsIChannel.LOAD_DOCUMENT_URI))
           channel.setRequestHeader("User-Agent", this.DESKTOP_UA, false);
+
         break;
       }
     }
   }
 };
 
 
 function nsBrowserAccess() {