iMyCircle

If you ever had trouble joining up with friends either in a city or in the wild (albeit with internet access) this app is for you. It will allow you to select friends from your contacts list and display the locations of the selected friends and your own on a Google map. For your convenience you can create groups of friends.
NOTE: This app does not require your friends to have iPhones. It also works with Android and Windows Phones, as long as your friends have also loaded the respective versions of this app (called 'MyCircle' on the other platforms) on their phones (or internet-capable) tablets.