Once the app is installed, you'll need to log in using your Ovi account username and password. You can add friends to the service by inputting their account details.
Impressively, IM for Nokia also lets you log into Google Talk, Windows Live Messenger, Yahoo Messenger and MySpace IM. The app has its own snazzy home-screen widget that'll tell you if you're chatting to anyone, as well as letting you change your status.
It's not all that different to other IM apps, but it's good to see Nokia rewarding customer loyalty. The app will come pre-installed on future Nokia mobiles, and you can find out more about it on Nokia's official blog.
It's not quite the same offering as Apple's newapp, which lets you send text messages for free over Wi-Fi and 3G connections. The IM for Nokia app will use your data, but, as it'll mostly just be text you're sending, we'd hazard it won't consume too much.
Coming just days after Apple's announcement, we wonder if Nokia's making a point that it too can offer free communication for its dedicated users.