diff --git a/src/I18n.php b/src/I18n.php
index d02ad04..a81e3de 100644
--- a/src/I18n.php
+++ b/src/I18n.php
@@ -128,8 +128,8 @@ class I18n {
       && Tpl :: initialized()
     ) {
       Tpl :: register_static_directory(self :: $root_path, null, 'locales/');
-      Tpl :: add_js_file("lib/babel.js", "js/translation.js");
-      Tpl :: add_js_file("locales/", "$locale.js");
+      Tpl :: add_js_file("lib/babel.js", "js/translation.js", 10);
+      Tpl :: add_js_file("locales/", "$locale.js", 11);
     }
 
     if (php_sapi_name() == 'cli') {
diff --git a/src/Tpl.php b/src/Tpl.php
index dc5e493..a471fd9 100644
--- a/src/Tpl.php
+++ b/src/Tpl.php
@@ -31,7 +31,7 @@ class Tpl {
    * Smarty templates directories path with their priority
    * @var array<string,int>
    */
-  public static $templates_directories = array();
+  public static $templates_directories = [];
 
   /**
    * Enable/disable AJAX returned data debugging in logs
@@ -49,19 +49,19 @@ class Tpl {
    * Static directories path with their priority
    * @var array<string,array>
    */
-  private static $static_directories = array();
+  private static $static_directories = [];
 
   /**
    * CSS files to load in next displayed page
    * @var array<string>
    */
-  private static $css_files = array();
+  private static $css_files = [];
 
   /**
    * JavaScript files to load in next displayed page
    * @var array<string>
    */
-  private static $js_files = array();
+  private static $js_files = [];
 
   /**
    * MIME type detector object
@@ -104,9 +104,9 @@ class Tpl {
         'cache_directory' => null,
         'main_pagetitle' => null,
         'static_root_url' => 'static/',
-        'static_directories' => array(),
-        'included_css_files' => array(),
-        'included_js_files' => array(),
+        'static_directories' => [],
+        'included_css_files' => ["css/app.css"],
+        'included_js_files' => ["js/app.js"],
         'webstats_js_code' => null,
         'upload_max_filesize' => null,
         'debug_ajax' => App::get('debug_ajax', false, 'bool'),
@@ -218,9 +218,9 @@ class Tpl {
 
     // Initialize errors & messages session variables
     if (!isset($_SESSION['errors']))
-      $_SESSION['errors'] = array();
+      $_SESSION['errors'] = [];
     if (!isset($_SESSION['messages']))
-      $_SESSION['messages'] = array();
+      $_SESSION['messages'] = [];
   }
 
   /**
@@ -404,7 +404,7 @@ class Tpl {
   public static function get_errors() {
     if(isset($_SESSION['errors']) && is_array($_SESSION['errors']))
         return $_SESSION['errors'];
-    return array();
+    return [];
   }
 
   /**
@@ -414,7 +414,7 @@ class Tpl {
   public static function get_messages() {
       if(isset($_SESSION['messages']) && is_array($_SESSION['messages']))
           return $_SESSION['messages'];
-      return array();
+      return [];
   }
 
   /**
@@ -462,7 +462,11 @@ class Tpl {
 
   /**
    * Register JS file(s) to load on next displayed page
-   * @param string|array<string> $args JS files to load
+   *
+   * Notes:
+   *  - if first argument matched with one declared static directories, used it as static root URL
+   *  - if last argument is an integer, used it as JS files inclusion priority
+   * @param string|int|array<string|int> $args JS files to load
    * @return void
    */
   public static function add_js_file(...$args) {
@@ -475,13 +479,23 @@ class Tpl {
       )
     )
       $root_url = self :: clean_static_root_url(array_shift($args));
-    foreach ($args as $files) {
-      if (!is_array($files)) $files = array($files);
-      foreach ($files as $file) {
-        $path = $root_url.$file;
-        if (!in_array($path, self :: $js_files))
-          self :: $js_files[] = $path;
-      }
+    $base_priority = (
+      count($args) > 1 && is_int($args[count($args)-1])?
+      intval(array_pop($args)):
+      ceil(max(max(self :: $js_files), 1000))+1
+    );
+    $files = call_user_func_array(
+      "array_merge",
+      array_map('\EesyPHP\ensure_is_array', $args)
+    );
+    foreach ($files as $idx => $file) {
+      $path = $root_url.$file;
+      $file_priority = $base_priority + 0.001 * $idx;
+      self :: $js_files[$path] = (
+        array_key_exists($path, self :: $js_files)?
+        min(self :: $js_files[$path], $file_priority):
+        $file_priority
+      );
     }
   }
 
@@ -510,7 +524,7 @@ class Tpl {
 
     // Handle CSS & JS files included
     self :: add_css_file(App::get('templates.included_css_files', null, 'array'));
-    self :: add_js_file(App::get('templates.included_js_files', null, 'array'));
+    self :: add_js_file(App::get('templates.included_js_files', null, 'array'), 500);
 
     // Messages
     self :: assign('errors', self :: get_errors());
@@ -518,7 +532,8 @@ class Tpl {
 
     // Files inclusions
     self :: assign('css', self :: $css_files);
-    self :: assign('js', self :: $js_files);
+    asort(self :: $js_files, SORT_NUMERIC);
+    self :: assign('js', array_keys(self :: $js_files));
 
     // I18n text domains
     self :: assign('CORE_TEXT_DOMAIN', I18n :: CORE_TEXT_DOMAIN);
@@ -647,7 +662,7 @@ class Tpl {
     $data=null, $error_code=null, $pretty=null, $keep_messages_on_success=false
   ) {
     if (!is_array($data))
-      $data = array();
+      $data = [];
 
     // Adjust HTTP error code on unsuccessful request (or if custom error code is provided)
     if (
@@ -876,7 +891,7 @@ class Tpl {
   public static function static_directories($details=false) {
     if ($details)
       return self :: $static_directories;
-    $result = array();
+    $result = [];
     foreach(self :: $static_directories as $root_url => $dirs)
       foreach(array_keys($dirs) as $dir)
         if (!in_array($dir, $result))
@@ -901,7 +916,7 @@ class Tpl {
     }
 
     if (!array_key_exists($root_url, self :: $static_directories)) {
-      self :: $static_directories[$root_url] = array();
+      self :: $static_directories[$root_url] = [];
       if (is_null($priority)) $priority = 100;
       $pattern = "#^(?P<root_url>$root_url)(?P<path>.*)#";
       Log :: trace(
diff --git a/templates/empty.tpl b/templates/empty.tpl
index 13a8fdd..cdee8b1 100644
--- a/templates/empty.tpl
+++ b/templates/empty.tpl
@@ -24,7 +24,6 @@
     <link href="{static_url path="lib/alertify-1.13.1/css/alertify.min.css"}" rel="stylesheet"/>
     <link href="{static_url path="lib/alertify-1.13.1/css/themes/bootstrap.min.css"}" rel="stylesheet"/>
 
-    <link href="{static_url path="css/app.css"}" rel="stylesheet"/>
     {foreach $css as $path}
       <link href="{$path|escape:"quotes"}" rel="stylesheet"/>
     {/foreach}
@@ -143,8 +142,6 @@
   <script src="{static_url path="lib/bootstrap-5.2.3/js/bootstrap.bundle.min.js"}"></script>
   <script src="{static_url path="lib/alertify-1.13.1/alertify.min.js"}"></script>
 
-  <script src="{static_url path="js/app.js"}"></script>
-
   <!-- Other libs & JavaScript scripts -->
 {foreach $js as $path}
   <script language="javascript" src="{$path|escape:"quotes"}"></script>