Unlike other 'find-me' iPhone applications, WTF focuses on users quickly asking how far away are you? 

A users location is displayed on a map along with home and office bookmarks.  This allows users to SEE how far away their friends and family are.

To further distinguish itself from other 'find-me' apps WTF also captures a users speed. Potentially useful information if you are wondering if your wife is stuck in traffic, or your son is driving safely.

And of course, safety being first... the location user's location is updated automatically every 1.5 kilometres.

WTF also allows a user to create a shared bookmark... enabling friends and family mark the map with a location to meet.

A common complaint about iPhone applications is that can only capture GPS coordinates while an application is running.  Realizing users needed incentives to use the application to capture their location, a parked car bookmark was also added to the application.  In real-time WTF updates the distance between the users current location - and the various bookmarks.