Wordpress Hiding the Update Notification / Remove dashboard widget / Hide help and options

Hide help and options

add_filter( 'contextual_help', 'mytheme_remove_help_tabs', 999, 3 );
function mytheme_remove_help_tabs($old_help, $screen_id, $screen){
    $screen->remove_help_tabs();
    return $old_help;
}

add_filter('screen_options_show_screen', '__return_false');  

Wordpress Hiding the Update Notification 

function hide_update_notice_to_all_but_admin_users()
{
    if (!current_user_can('update_core')) {
        remove_action( 'admin_notices', 'update_nag', 3 );
    }
}
add_action( 'admin_head', 'hide_update_notice_to_all_but_admin_users', 1 );

 Remove Dashboard widget 

function remove_dashboard_widgets () {

  remove_meta_box('dashboard_quick_press','dashboard','side'); //Quick Press widget
  remove_meta_box('dashboard_recent_drafts','dashboard','side'); //Recent Drafts
  remove_meta_box('dashboard_primary','dashboard','side'); //WordPress.com Blog
  remove_meta_box('dashboard_secondary','dashboard','side'); //Other WordPress News
  remove_meta_box('dashboard_incoming_links','dashboard','normal'); //Incoming Links
  remove_meta_box('dashboard_plugins','dashboard','normal'); //Plugins
  remove_meta_box('dashboard_right_now','dashboard', 'normal'); //Right Now
  remove_meta_box('rg_forms_dashboard','dashboard','normal'); //Gravity Forms
  remove_meta_box('dashboard_recent_comments','dashboard','normal'); //Recent Comments
  remove_meta_box('icl_dashboard_widget','dashboard','normal'); //Multi Language Plugin
  remove_meta_box('dashboard_activity','dashboard', 'normal'); //Activity
  remove_action('welcome_panel','wp_welcome_panel');

}

add_action('wp_dashboard_setup', 'remove_dashboard_widgets');