Facebook Gadget is a Widgets software developed by Google. After our trial and test, the software is proved to be official, secure and free. Here is the official description for Facebook Gadget:

Edit by Marydown: Facebook Gadget can help you get Facebook notifications on your desktop.Once you get a new facebook message, it will post desktop notifications. With this widget, you don't have to continuously check facebook to see if someone responded to a message you wrote them.