Various wordpress functions to modify wordpress admin in plugins

<?php 
/*--------------------------------------------------------------
    CHANGE FOOTER ADMIN
--------------------------------------------------------------*/ 
function btwp_change_footer_admin () {
    echo 'Theme developed by <a href="https://github.com/theandersonn" target="_blank">theandersonn</a>. Powered by <a href="http://www.wordpress.org" target="_blank">WordPress</a>';
}

add_filter('admin_footer_text', 'btwp_change_footer_admin');

?>

<?php 

/*--------------------------------------------------------------
    CHANGE LOGIN LABEL USERNAME
--------------------------------------------------------------*/ 
add_action( 'login_head', 'login_function' );

function login_function() {
    add_filter( 'gettext', 'username_change', 20, 3 );
    
    function username_change( $translated_text, $text, $domain ) {
        if ( $text === 'Username or Email Address' ) {
            $translated_text = 'OTHER NAME HERE';
        }
        return $translated_text;
    }
}
?>

<?php 

/*--------------------------------------------------------------
    CHANGE POST LABEL
--------------------------------------------------------------*/ 

add_action( 'admin_menu', 'change_post_label' );
add_action( 'init', 'change_post_object' );

function change_post_label() {
    global $menu;
    global $submenu;
    $menu[5][0] = 'Mídias';
    $submenu['edit.php'][5][0] = 'Mídias';
    $submenu['edit.php'][10][0] = 'Adicionar Mídia';
    $submenu['edit.php'][16][0] = 'Tags';
    echo '';
}

function change_post_object() {
    global $wp_post_types;
    $labels = &$wp_post_types['post']->labels;
    $labels->name = 'Mídias';
    $labels->singular_name = 'Mídia';
    $labels->add_new = 'Adicionar Mídia';
    $labels->add_new_item = 'Adicionar Mídia';
    $labels->edit_item = 'Editar Mídia';
    $labels->new_item = 'Mídia';
    $labels->view_item = 'Ver Mídia';
    $labels->search_items = 'Buscar Mídias';
    $labels->not_found = 'Nenhum Mídia encontrado';
    $labels->not_found_in_trash = 'Nenhum Mídia encontrado no Lixo';
    $labels->all_items = 'Todos Mídias';
    $labels->menu_name = 'Mídias';
    $labels->name_admin_bar = 'Mídias';
} 

<?php
/*--------------------------------------------------------------
    DISABLE DRAG METABOX DASHBOARD
--------------------------------------------------------------*/
add_action( 'admin_init', 'btwp_disable_drag_metabox_dashboard' );

function btwp_disable_drag_metabox_dashboard() {
    wp_deregister_script( 'postbox' );
}

<?php
/*--------------------------------------------------------------
  HIDE ITEM MENU DASHBOARD
--------------------------------------------------------------*/
add_action( 'admin_menu', 'btwp_hide_item_menu_dashboard' );

function btwp_hide_item_menu_dashboard(){
  
  if( !(current_user_can('administrator')) ) {
    remove_menu_page( 'index.php' );                  //Dashboard
    remove_menu_page( 'edit.php' );                   //Posts
    remove_menu_page( 'upload.php' );                 //Media
    remove_menu_page( 'edit.php?post_type=page' );    //Pages
    remove_menu_page( 'edit-comments.php' );          //Comments
    remove_menu_page( 'themes.php' );                 //Appearance
    remove_menu_page( 'plugins.php' );                //Plugins
    remove_menu_page( 'users.php' );                  //Users
    remove_menu_page( 'tools.php' );                  //Tools
    remove_menu_page( 'options-general.php' );        //Settings
  }
  
}

<?php
/*--------------------------------------------------------------
INSERE WIDGET PERSONALIZADO NO DASHBOARD ADMIN
--------------------------------------------------------------*/
function btwp_insert_custom_dashboard_widgets() {
    global $wp_meta_boxes;
    wp_add_dashboard_widget('custom_help_widget', 'Contate o desenvolvedor', 'btwp_insert_custom_dashboard_help');
}

function btwp_insert_custom_dashboard_help() {
    echo '<p>Bem vindo ao sistema do site nome da empresa! Precisa de Ajuda? Contate o desenvolvedor <a href="mailto:email@email.com.br">aqui</a>. Para aceesar o nosso site, visite: <a href="http://www.nome-site.com.br" target="_blank">Nome do Site</a></p>';
}

add_action('wp_dashboard_setup', 'btwp_insert_custom_dashboard_widgets');

<?php
/*--------------------------------------------------------------
    INSERT LINK TO THE WP TOOLBAR
--------------------------------------------------------------*/  
function btwp_insert_custom_toolbar_link($wp_admin_bar) {
    $args = array(
        'id' => 'andersonn',
        'title' => 'Fale com Andersonn', 
        'href' => 'https://github.com/theandersonn', 
        'meta' => array(
            'class' => 'andersonn', 
            'title' => 'Fale com Andersonn'
            )
    );
    $wp_admin_bar->add_node($args);
}
add_action('admin_bar_menu', 'btwp_insert_custom_toolbar_link', 999);

<?php 
/*--------------------------------------------------------------
    INSERT USER ID COLUMN
--------------------------------------------------------------*/ 
// Adding the column
add_filter( 'manage_users_columns', 'btwp_user_id_column' );

function btwp_user_id_column( $columns ) {
    $columns['user_id'] = 'ID';
    return $columns;
}

// Column content
add_action( 'manage_users_custom_column',  'btwp_user_id_column_content', 10, 3 );

function btwp_user_id_column_content( $value, $column_name, $user_id ) {
    if ( 'user_id' == $column_name )
        return $user_id;
    return $value;
}


// Column style
add_action( 'admin_head-users.php',  'btwp_user_id_column_style' );

function btwp_user_id_column_style() {
    echo '<style>.column-user_id{width: 5%}</style>';
}

MIT Licensed Code