This is one of the items that is tested in your Windows 8 App when you use the WACK.
If you are in Southern California, please email this posts for more information on getting a token for your app by June 30, 2012!
The search contract lets your users search through your app’s content from anywhere in the system. Using the Search charm helps you:
Take advantage of muscle memory that users have built by using the Search charm in the system and in other apps Ensure that users have a consistent and predictable experience when they search and when they change search settings Make your app more visible by placing it at the top of the list of searchable apps if the user searches your app frequently