Samsung may be behind ChatON, but you can download and use it on any Android phone or tablet, or on your browser. It's an instant messenger service like AIM, GChat or Facebook Chat, and lets you send free instant messages, videos or even your own doodles to anyone, not just people with Samsung phones.
BBM and iMessage only send messages to other people with BlackBerry or Apple phones and tablets, making ChatON an attractive prospect right from the off. Your friends will need the ChatON app too though, and there are plenty of other Android IM apps, such as WhatsApp.
As well as the usual IM chats, ChatON lets you send video, audio or picture messages, or a map of your location. You can also chat in groups, and see the people you chat to most with Interaction Rank. Our favourite feature is the option to doodle a picture and send that.
If a friend is offline, you can use the Buddies Say feature to leave comments for them on their profile pages. And you can chat through your computer too.
Of course, chatting like this while out and about uses data, so it's only free on Wi-Fi or if you've got a decent data allowance. But it's more sophisticated than a simple text message, and is especially handy for not being tied to just people who have the same phone as you.