It’s really Find My iPhone but since my wife happens to use an iPhone, for me this app is all about finding my wife.
The application (for Windows Phone in case you didn’t get that) uses the mobile me find my iphone service to locate all your registered iOS devices.
Anyways, it’s coming along nicely.

Is there a way for your wife to decide if she wants to share her location each time?
She can disable the mobile me location service anytime.