function example_dashboard_widget_function() {
	// Display whatever it is you want to show
	echo "Hello World, I'm a great Dashboard Widget";
} 

// Create the function use in the action hook
function example_add_dashboard_widgets() {
	wp_add_dashboard_widget('example_dashboard_widget', 'Example Dashboard Widget', 'example_dashboard_widget_function');
}
// Hoook into the 'wp_dashboard_setup' action to register our other functions
add_action('wp_dashboard_setup', 'example_add_dashboard_widgets' );

Custom Admin Dashboard Widget

wordpress

PHP