Hook/notify when any option or setting is added or updated

Looking at the sources (core files, wp-includes/option.php) you can always find your target hook tags:

add_action('added_option', 'wpse230212_callback_add', 10, 2);
add_action('updated_option', 'wpse230212_callback_update', 10, 3);

function wpse230212_callback_add( $option_name, $option_value ) {
    // do stuff on add_option
}

function wpse230212_callback_update( $option_name, $old_value, $option_value ) {
    // do stuff on update_option    
}

Hope that helps.