Existing friend-locating apps are not straightforward to use. They require you to define your friends. That's boring and there is a chance of you forgetting some of your friends. Then, you have to open the app, maybe ask your friends for permission to see where they are, then wait for the app to locate your friends or refresh the information. What if you're in a pub and there's no Internet coverage? You won't know if any your friends are in the same pub.
Nowy Friends is super simple to use: install, sign in with Facebook, and you're done. No need to re-add your friends. The app automatically imports your list of friends from Facebook who also use Nowy Friends. Nowy Friends even automatically notifies you when a friend shows up.