Inagist_chrome_extension is a project mainly written in JavaScript, it's free.
Chrome notirication extension for inagist.com
This extension brings real-time notifications from inagist.com to your browser. Even while you are not on inagist.com when a story is trending for your account on inagist.com or a tweet is gaining popularity, this extension will pop-up a notification alert.
Once you install this extension go to the options of the extension and give your twitter user name which you used to sign in to inagist.com. The extension will connect and wait for alerts for that account.
All your custom channels which you have configured in your settings page on inagist.com will also send alerts to the extension.