This app adds a possibility to say "Hello" to the other site members. Similar functionality is available in Dolphin (Send Greeting/Send Kiss) and the other social networks.
For now a greeting can be sent from view profile page (see screenshot №1). Site member who received a greeting will see it in My Greetings block which is available on Dashboard and Profile View pages (see screenshot №2). Also he'll be notified via default UNA's Notifications app (see screenshot №3).