Contact corral allows users to find contacts in their contact list depending on the city and state they put in.
They can even choose the radius from which to search.
Example 1:
Travel to Miami and you want to know is in your contacts from Miami. Open the app and it will find contacts with that area code or 10 - 50 mile radius of it.
Example 2:
Thinking about going to Houston, Texas but not sure if you know anyone there. Plug in the city and the app will search your contacts and let you know who you know in that city.
Same with any other city in America.