diff --git a/Zotlabs/Module/Cal.php b/Zotlabs/Module/Cal.php
index 003d63c6d..9fa095f5a 100644
--- a/Zotlabs/Module/Cal.php
+++ b/Zotlabs/Module/Cal.php
@@ -1,6 +1,8 @@
 <?php
 namespace Zotlabs\Module;
 
+use Zotlabs\Lib\Apps;
+
 require_once('include/conversation.php');
 require_once('include/bbcode.php');
 require_once('include/datetime.php');
@@ -152,7 +154,7 @@ class Cal extends \Zotlabs\Web\Controller {
 			if(! $f)
 				$f = 'ymd';
 	
-			$catsenabled = feature_enabled($channel['channel_id'],'categories');
+			$catsenabled = Apps::system_app_installed(local_channel(),'Categories');
 	
 	
 			$show_bd = perm_is_allowed($channel['channel_id'], get_observer_hash(), 'view_contacts');
diff --git a/Zotlabs/Module/Card_edit.php b/Zotlabs/Module/Card_edit.php
index 694bdc4ea..3b22ca916 100644
--- a/Zotlabs/Module/Card_edit.php
+++ b/Zotlabs/Module/Card_edit.php
@@ -1,6 +1,8 @@
 <?php
 namespace Zotlabs\Module;
 
+use Zotlabs\Lib\Apps;
+
 require_once('include/channel.php');
 require_once('include/acl_selectors.php');
 require_once('include/conversation.php');
@@ -59,7 +61,7 @@ class Card_edit extends \Zotlabs\Web\Controller {
 
 
 		$category = '';
-		$catsenabled = ((feature_enabled($owner,'categories')) ? 'categories' : '');
+		$catsenabled = ((Apps::system_app_installed($owner,'Categories')) ? 'categories' : '');
 
 		if ($catsenabled){
 		        $itm = fetch_post_tags($itm);
diff --git a/Zotlabs/Module/Cards.php b/Zotlabs/Module/Cards.php
index 78cbad5fd..28866b69f 100644
--- a/Zotlabs/Module/Cards.php
+++ b/Zotlabs/Module/Cards.php
@@ -123,7 +123,7 @@ class Cards extends Controller {
 				'layoutselect'      => false,
 				'expanded'          => false,
 				'novoting'          => false,
-				'catsenabled'       => feature_enabled($owner, 'categories'),
+				'catsenabled'       => Apps::system_app_installed($owner, 'Categories'),
 				'bbco_autocomplete' => 'bbcode',
 				'bbcode'            => true
 			];
diff --git a/Zotlabs/Module/Categories.php b/Zotlabs/Module/Categories.php
new file mode 100644
index 000000000..92d638086
--- /dev/null
+++ b/Zotlabs/Module/Categories.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Zotlabs\Module;
+
+use Zotlabs\Lib\Apps;
+use Zotlabs\Lib\Libsync;
+use Zotlabs\Web\Controller;
+
+class Categories extends Controller {
+
+
+	function get() {
+
+        $desc = t('This app allows you to add categories to posts and events.');
+
+        $text = '<div class="section-content-info-wrapper">' . $desc . '</div>';
+
+        if(! ( local_channel() && Apps::system_app_installed(local_channel(),'Categories'))) {
+            return $text;
+        }
+
+	}
+
+
+}
\ No newline at end of file
diff --git a/Zotlabs/Module/Editpost.php b/Zotlabs/Module/Editpost.php
index df46ab78d..e1f5c6baf 100644
--- a/Zotlabs/Module/Editpost.php
+++ b/Zotlabs/Module/Editpost.php
@@ -1,6 +1,8 @@
 <?php
 namespace Zotlabs\Module; /** @file */
 
+use Zotlabs\Lib\Apps;
+
 require_once('include/acl_selectors.php');
 require_once('include/taxonomy.php');
 require_once('include/conversation.php');
@@ -51,7 +53,7 @@ class Editpost extends \Zotlabs\Web\Controller {
 		$channel = \App::get_channel();
 
 		$category = '';
-		$catsenabled = ((feature_enabled($owner_uid,'categories')) ? 'categories' : '');
+		$catsenabled = ((Apps::system_app_installed($owner_uid,'Categories')) ? 'categories' : '');
 
 		if ($catsenabled){
 		        $itm = fetch_post_tags($itm);
diff --git a/Zotlabs/Module/Events.php b/Zotlabs/Module/Events.php
index 339419e6d..1e40b58cf 100644
--- a/Zotlabs/Module/Events.php
+++ b/Zotlabs/Module/Events.php
@@ -2,6 +2,7 @@
 namespace Zotlabs\Module;
 
 use Zotlabs\Lib\Libsync;
+use Zotlabs\Lib\Apps;
 
 require_once('include/conversation.php');
 require_once('include/bbcode.php');
@@ -422,7 +423,7 @@ class Events extends \Zotlabs\Web\Controller {
 			if(! $f)
 				$f = 'ymd';
 	
-			$catsenabled = feature_enabled(local_channel(),'categories');
+			$catsenabled = Apps::system_app_installed(local_channel(),'Categories');
 	
 			$category = '';
 	
diff --git a/Zotlabs/Widget/Categories.php b/Zotlabs/Widget/Categories.php
index ea250b46b..c35137757 100644
--- a/Zotlabs/Widget/Categories.php
+++ b/Zotlabs/Widget/Categories.php
@@ -42,7 +42,7 @@ class Categories {
 
 	static function articlecategories_widget($baseurl,$selected = '') {
 	
-		if(! feature_enabled(App::$profile['profile_uid'],'categories'))
+		if(! Apps::system_app_installed(App::$profile['profile_uid'],'Categories'))
 			return '';
 
 		$sql_extra = item_permissions_sql(App::$profile['profile_uid']);
@@ -86,7 +86,7 @@ class Categories {
 
 	static function cardcategories_widget($baseurl,$selected = '') {
 	
-		if(! feature_enabled(App::$profile['profile_uid'],'categories'))
+		if(! Apps::system_app_installed(App::$profile['profile_uid'],'Categories'))
 			return '';
 
 		$sql_extra = item_permissions_sql(App::$profile['profile_uid']);
@@ -131,7 +131,7 @@ class Categories {
 
 	static function categories_widget($baseurl,$selected = '') {
 	
-		if(! feature_enabled(App::$profile['profile_uid'],'categories'))
+		if(! Apps::system_app_installed(App::$profile['profile_uid'],'Categories'))
 			return '';
 
 		require_once('include/security.php');
diff --git a/app/categories.apd b/app/categories.apd
new file mode 100644
index 000000000..c55bead7e
--- /dev/null
+++ b/app/categories.apd
@@ -0,0 +1,6 @@
+version: 1
+url: $baseurl/categories
+requires: local_channel
+name: Categories
+photo: icon:tags
+categories: Networking
diff --git a/include/conversation.php b/include/conversation.php
index 2a35a90f5..f67b30cb6 100644
--- a/include/conversation.php
+++ b/include/conversation.php
@@ -1,5 +1,6 @@
 <?php /** @file */
 
+use Zotlabs\Lib\Apps;
 
 function item_extract_images($body) {
 
@@ -1325,7 +1326,7 @@ function z_status_editor($a, $x, $popup = false) {
 	if(array_key_exists('catsenabled',$x))
 		$catsenabled = $x['catsenabled'];
 	else
-		$catsenabled = ((feature_enabled($x['profile_uid'], 'categories') && (! $webpage)) ? 'categories' : '');
+		$catsenabled = ((Apps::system_app_installed($x['profile_uid'], 'Categories') && (! $webpage)) ? 'categories' : '');
 
 	// avoid illegal offset errors
 	if(! array_key_exists('permissions',$x)) 
diff --git a/include/taxonomy.php b/include/taxonomy.php
index 46d95458c..3e8f69dfb 100644
--- a/include/taxonomy.php
+++ b/include/taxonomy.php
@@ -481,6 +481,10 @@ function wtagblock($uid,$count = 0,$authors = '',$owner = '', $flags = 0,$restri
 function catblock($uid,$count = 0,$authors = '',$owner = '', $flags = 0,$restrict = 0,$type = TERM_CATEGORY) {
 	$o = '';
 
+	if(! Apps::system_app_installed($uid,'Categories')) {
+		return $o;
+	}
+
 	$r = tagadelic($uid,$count,$authors,$owner,$flags,$restrict,$type);
 
 	if($r) {