Shows the current environment type in the WordPress admin footer to help developers avoid editing the wrong site.
add_filter( 'admin_footer_text', 'wpfolks_admin_environment_footer' );
function wpfolks_admin_environment_footer( $text ) {
$environment = wp_get_environment_type();
return sprintf( '%s <span style="opacity:.7">Environment: %s</span>', $text, esc_html( $environment ) );
}