diff --git a/app/assets/javascripts/app/services/authManager.js b/app/assets/javascripts/app/services/authManager.js
index 2c6d4c7e9..6c2be7612 100644
--- a/app/assets/javascripts/app/services/authManager.js
+++ b/app/assets/javascripts/app/services/authManager.js
@@ -299,14 +299,14 @@ angular.module('app.frontend')
         console.log("AuthManager received resolved UserPreferences", resolvedSingleton);
         this.userPreferences = resolvedSingleton;
         this.userPreferencesDidChange();
-      }, () => {
+      }, (valueCallback) => {
         // Safe to create. Create and return object.
         var prefs = new Item({content_type: prefsContentType});
         modelManager.addItem(prefs);
         prefs.setDirty(true);
         console.log("Created new prefs", prefs);
         $rootScope.sync();
-        return prefs;
+        valueCallback(prefs);
       });
 
       this.userPreferencesDidChange = function() {
diff --git a/app/assets/javascripts/app/services/directives/views/roomBar.js b/app/assets/javascripts/app/services/directives/views/roomBar.js
index 63f3d89e4..f237f1aa7 100644
--- a/app/assets/javascripts/app/services/directives/views/roomBar.js
+++ b/app/assets/javascripts/app/services/directives/views/roomBar.js
@@ -7,16 +7,14 @@ class RoomBar {
     };
   }
 
-  controller($rootScope, $scope, desktopManager, syncManager, modelManager, componentManager, $timeout) {
+  controller($rootScope, $scope, desktopManager, syncManager, modelManager, componentManager, $timeout, singletonManager, packageManager) {
     'ngInject';
 
     $scope.componentManager = componentManager;
     $scope.rooms = [];
 
     modelManager.addItemSyncObserver("room-bar", "SN|Component", (allItems, validItems, deletedItems, source) => {
-      $scope.rooms = _.uniq($scope.rooms
-        .concat(allItems
-        .filter((candidate) => {return candidate.area == "rooms"})))
+      $scope.rooms = _.uniq($scope.rooms.concat(allItems.filter((candidate) => {return candidate.area == "rooms"})))
         .filter((candidate) => {return !candidate.deleted});
     });
 
@@ -55,6 +53,18 @@ class RoomBar {
       room.show = false;
       this.componentManager.deactivateComponent(room);
     }
+
+    // Handle singleton ProLink instance
+    singletonManager.registerSingleton({content_type: "SN|Component", package_info: {identifier: "org.standardnotes.prolink"}}, (resolvedSingleton) => {
+      console.log("Roombar received resolved ProLink", resolvedSingleton);
+    }, (valueCallback) => {
+      console.log("Creating prolink");
+      // Safe to create. Create and return object.
+      let url = window._prolink_package_url;
+      packageManager.installPackage(url, (component) => {
+        valueCallback(component);
+      })
+    });
   }
 
 
diff --git a/app/assets/javascripts/app/services/modelManager.js b/app/assets/javascripts/app/services/modelManager.js
index 70438bc0b..c4f475a7b 100644
--- a/app/assets/javascripts/app/services/modelManager.js
+++ b/app/assets/javascripts/app/services/modelManager.js
@@ -3,6 +3,7 @@ class ModelManager {
   constructor(storageManager) {
     ModelManager.MappingSourceRemoteRetrieved = "MappingSourceRemoteRetrieved";
     ModelManager.MappingSourceRemoteSaved = "MappingSourceRemoteSaved";
+    ModelManager.MappingSourceLocalSaved = "MappingSourceLocalSaved";
     ModelManager.MappingSourceLocalRetrieved = "MappingSourceLocalRetrieved";
     ModelManager.MappingSourceComponentRetrieved = "MappingSourceComponentRetrieved";
     ModelManager.MappingSourceRemoteActionRetrieved = "MappingSourceRemoteActionRetrieved"; /* aciton-based Extensions like note history */
@@ -103,6 +104,10 @@ class ModelManager {
     return tag;
   }
 
+  didSyncModelsOffline(items) {
+    this.notifySyncObserversOfModels(items, ModelManager.MappingSourceLocalSaved);
+  }
+
   mapResponseItemsToLocalModels(items, source) {
     return this.mapResponseItemsToLocalModelsOmittingFields(items, null, source);
   }
diff --git a/app/assets/javascripts/app/services/singletonManager.js b/app/assets/javascripts/app/services/singletonManager.js
index 3f6d260e7..70f92fd96 100644
--- a/app/assets/javascripts/app/services/singletonManager.js
+++ b/app/assets/javascripts/app/services/singletonManager.js
@@ -45,7 +45,7 @@ class SingletonManager {
   }
 
   resolveSingletons(retrievedItems, initialLoad) {
-    for(var singletonHandler of this.singletonHandlers) {
+    for(let singletonHandler of this.singletonHandlers) {
       var predicate = singletonHandler.predicate;
       var singletonItems = this.filterItemsWithPredicate(retrievedItems, predicate);
       if(singletonItems.length > 0) {
@@ -63,7 +63,7 @@ class SingletonManager {
         */
         if(allExtantItemsMatchingPredicate.length >= 2) {
           var toDelete = [];
-          for(var extantItem of allExtantItemsMatchingPredicate) {
+          for(let extantItem of allExtantItemsMatchingPredicate) {
             if(!singletonItems.includes(extantItem)) {
               // Delete it
               toDelete.push(extantItem);
@@ -102,10 +102,13 @@ class SingletonManager {
         // Retrieved items does not include any items of interest. If we don't have a singleton registered to this handler,
         // we need to create one. Only do this on actual sync completetions and not on initial data load. Because we want
         // to get the latest from the server before making the decision to create a new item
-        if(!singletonHandler.singleton && !initialLoad) {
-          var item = singletonHandler.createBlock();
-          singletonHandler.singleton = item;
-          singletonHandler.resolutionCallback(item);
+        if(!singletonHandler.singleton && !initialLoad && !singletonHandler.pendingCreateBlockCallback) {
+          singletonHandler.pendingCreateBlockCallback = true;
+          singletonHandler.createBlock((created) => {
+            singletonHandler.singleton = created;
+            singletonHandler.pendingCreateBlockCallback = false;
+            singletonHandler.resolutionCallback(created);
+          });
         }
       }
     }
@@ -113,13 +116,25 @@ class SingletonManager {
 
   filterItemsWithPredicate(items, predicate) {
     return items.filter((candidate) => {
-      for(var key in predicate) {
-        if(candidate[key] != predicate[key]) {
+      return this.itemSatisfiesPredicate(candidate, predicate);
+    })
+  }
+
+  itemSatisfiesPredicate(candidate, predicate) {
+    for(var key in predicate) {
+      var predicateValue = predicate[key];
+      var candidateValue = candidate[key];
+      if(typeof predicateValue == 'object') {
+        // Check nested properties
+        if(!this.itemSatisfiesPredicate(candidateValue, predicateValue)) {
           return false;
         }
       }
-      return true;
-    })
+      else if(candidateValue != predicateValue) {
+        return false;
+      }
+    }
+    return true;
   }
 
 }
diff --git a/app/assets/javascripts/app/services/syncManager.js b/app/assets/javascripts/app/services/syncManager.js
index 17f13fd78..571aac588 100644
--- a/app/assets/javascripts/app/services/syncManager.js
+++ b/app/assets/javascripts/app/services/syncManager.js
@@ -64,6 +64,9 @@ class SyncManager {
 
       this.$rootScope.$broadcast("sync:completed", {});
 
+      // Required in order for modelManager to notify sync observers
+      this.modelManager.didSyncModelsOffline(items);
+
       if(callback) {
         callback({success: true});
       }
diff --git a/app/views/application/frontend.html.erb b/app/views/application/frontend.html.erb
index c1dea5432..28d3fb2c9 100644
--- a/app/views/application/frontend.html.erb
+++ b/app/views/application/frontend.html.erb
@@ -30,6 +30,7 @@
 
     <script>
       window._default_sf_server = "<%= ENV['SF_DEFAULT_SERVER'] %>";
+      window._prolink_package_url = "<%= ENV['PROLINK_URL'] %>";
     </script>
 
     <% if Rails.env.development? %>