I have a ticketing web application written with PHP and MySQL. I need something like windows balloon or gmail desktop notifier for Chrome to notify users about some events. For example, when a new ticket arrives to a users, he/she can be notified about it without need to see the application page.
Is there anything for this that can work with PHP and MySQL ?
You want to build a chrome extension for showing desktop notification of your tickets. To do that, you will need PHP and MySQL at the backend AND the actual Chrome extension written in JavaScript and HTML. You can write the notification window using JavaScript and HTML packaged inside your Chrome extension.
Here is a link showing how to build a basic extension and here is another one on desktop notifications. Keep in mind that desktop notifications in Chrome popup outside the browser. However, if you are familiar with JavaScript and HTML, you should be able to achieve what you require.
Keep us posted on your progress and/or if you run into trouble.