This is a yii2 widget, which makes use of jgrowl plugin (see here)
Installation:
composer require joker7789/yiigrowl:dev-master
Usage example (in your view/layout for example):
<?=\joker7789\yiigrowl\Growl::widget([
'message' => "Hello World",
'options' => ['header' => 'testing header'],
]);?>
cheers,
zckri