To use the functions "Friends" and "Messages" in iPeak app you must be registered.
See how to register here.
To find friends on ski resort use the search at the top of the screen (slide 1/5).
After you've selected a user from the list (slide 2/5) you can send a message or send a friend request (slide 3/5). The request is indicated by the figure on the icon "Friends" on the desktop (main screen) of the application. The signal about messages works analogously.
In order to see your friend requests you can click on the icon in the upper right corner of the screen (slide 1/5).
Use friends' profile (slide 4/5) to see friends' location on the ski resort (slide 5/5), send a message or delete him from your list of friends.
Enjoy your iPeak application :)