Index: src/social/model/Person.php
===================================================================
--- src/social/model/Person.php	(revision 755023)
+++ src/social/model/Person.php	(working copy)
@@ -33,6 +33,7 @@
   public $activities;
   public $addresses;
   public $age;
+  public $appData;
   public $birthday;
   public $bodyType;
   public $books;
@@ -155,6 +156,14 @@
     $this->setFieldImpl('age', $age);
   }
 
+  public function getAppData() {
+    return $this->appData;
+  }
+  
+  public function setAppData($appData) {
+    $this->setFieldImpl('appData', $appData);
+  }
+  
   public function getBirthday() {
     return $this->birthday;
   }
Index: src/social/service/PersonHandler.php
===================================================================
--- src/social/service/PersonHandler.php	(revision 755023)
+++ src/social/service/PersonHandler.php	(working copy)
@@ -27,7 +27,9 @@
 
   public function __construct() {
     $service = Config::get('person_service');
+    $appDataService = Config::get('app_data_service');
     $this->personService = new $service();
+    $this->appDataService = new $appDataService();
   }
 
   public function handleDelete(RequestItem $request) {
@@ -42,6 +44,19 @@
     throw new SocialSpiException("You can't add people right now.", ResponseError::$NOT_IMPLEMENTED);
   }
 
+  public function mergePersonAndData(&$person, DataCollection $data) {
+    $data_entry = $data->getEntry();
+    $person["appData"] = $data_entry[$person["id"]];  // PHP copies arrays by value
+  }
+  
+  public function mergePeopleAndData(&$people, DataCollection $data) {
+    $people_entries = $people->getEntry();
+    foreach ($people_entries as &$person) {
+      $this->mergePersonAndData($person, $data);
+    }
+    $people->setEntry($people_entries);
+  }
+  
   /**
    * Allowed end-points /people/{userId}+/{groupId} /people/{userId}/{groupId}/{optionalPersonId}+
    *
@@ -62,6 +77,24 @@
       throw new IllegalArgumentException("Cannot fetch personIds for multiple userIds");
     }
     
+    // Check for app data fields
+    $appDataFields = array();
+    $personFields = array();
+    $fetchAppData = False;
+    foreach ($fields as $field) {
+      if ($field === "appData") {
+        $appDataFields[] = "*";
+        $fetchAppData = True;
+        break;
+      } else if (substr($field, 0, 8) === "appData.") {
+        $appDataFields[] = substr($field, 8);
+        $fetchAppData = True;
+      } else {
+        $personFields[] = $field;
+      }
+    }
+    $fields = $personFields;
+    
     $options = new CollectionOptions();
     $options->setSortBy($request->getSortBy());
     $options->setSortOrder($request->getSortOrder());
@@ -74,22 +107,48 @@
     if (count($userIds) == 1) {
       if (count($optionalPersonId) == 0) {
         if ($groupId->getType() == 'self') {
-          return $this->personService->getPerson($userIds[0], $groupId, $fields, $request->getToken());
+          $person = $this->personService->getPerson($userIds[0], $groupId, $fields, $request->getToken());
+          if ($fetchAppData) {
+            $appData = $this->appDataService->getPersonData($userIds[0], $groupId, $request->getAppId(), $appDataFields, $request->getToken());
+            $this->mergePersonAndData($person, $appData);
+          }
+          return $person;
         } else {
-          return $this->personService->getPeople($userIds, $groupId, $options, $fields, $request->getToken());
+          $people = $this->personService->getPeople($userIds, $groupId, $options, $fields, $request->getToken());
+          if ($fetchAppData) {
+            $appData = $this->appDataService->getPersonData($userIds, $groupId, $request->getAppId(), $appDataFields, $request->getToken());
+            $this->mergePeopleAndData($people, $appData);
+          }
+          return $people;
         }
       } elseif (count($optionalPersonId) == 1) {
-        return $this->personService->getPerson($optionalPersonId[0], $groupId, $fields, $request->getToken());
+        $person = $this->personService->getPerson($optionalPersonId[0], $groupId, $fields, $request->getToken());
+        if ($fetchAppData) {
+          $appData = $this->appDataService->getPersonData($optionalPersonId[0], $groupId, $request->getAppId(), $appDataFields, $request->getToken());
+          $this->mergePersonAndData($person, $appData);
+        }
+        return $person;
       } else {
         $personIds = array();
         foreach ($optionalPersonId as $pid) {
           $personIds[] = new UserId('userId', $pid);
         }
         // Every other case is a collection response of optional person ids
-        return $this->personService->getPeople($personIds, new GroupId('self', null), $options, $fields, $request->getToken());
+        $groupId = new GroupId('self', null);
+        $people = $this->personService->getPeople($personIds, $groupId, $options, $fields, $request->getToken());
+        if ($fetchAppData) {
+          $appData = $this->appDataService->getPersonData($personIds, $groupId, $request->getAppId(), $appDataFields, $request->getToken());
+          $this->mergePeopleAndData($people, $appData);
+        }
+        return $people;
       }
     }
     // Every other case is a collection response.
-    return $this->personService->getPeople($userIds, $groupId, $options, $fields, $request->getToken());
+    $people = $this->personService->getPeople($userIds, $groupId, $options, $fields, $request->getToken());
+    if ($fetchAppData) {
+      $appData = $this->appDataService->getPersonData($userIds, $groupId, $request->getAppId(), $appDataFields, $request->getToken());
+      $this->mergePeopleAndData($people, $appData);
+    }
+    return $people;
   }
 }
Index: src/social/service/RequestItem.php
===================================================================
--- src/social/service/RequestItem.php	(revision 755023)
+++ src/social/service/RequestItem.php	(working copy)
@@ -64,7 +64,7 @@
 
   public function getAppId() {
     $appId = $this->getParameter(self::$APP_ID);
-    if ($appId != null && $appId == self::$APP_SUBSTITUTION_TOKEN) {
+    if ($appId != null && $appId == self::$APP_SUBSTITUTION_TOKEN || !$appId) {
       return $this->token->getAppId();
     } else {
       return $appId;