public static function get_icon_for_extension($extension)
    {
        $extension = strtolower($extension);
        $module = ModuleLoader::getModule('silverstripe/framework');

        $candidates = [
            $extension,
            static::get_app_category($extension),
            'generic'
        ];
        foreach ($candidates as $candidate) {
            $resource = $module->getResource("client/images/app_icons/{$candidate}_92.png");
            if ($resource->exists()) {
                return $resource->getURL();
            }
        }
        return null;
    }