The application allows you to communicate with text or audio. For both possibilities you will need to have a permanent Internet connection. This is the only way to communicate with your contacts.
As usual with this type of service, you can add pictures and videos to your conversations, create an avatar, and change your status.
SayHi has something that distinguishes it from other applications of this type, a popularity system. This acts like a game, and gives you the chance to stand out from other users, and make yourself more visible.
SayHi is a very distinctive communication tool that makes getting to know new people in your city like a game, just as much fun on your mobile phone as in person.