While BlackBerry's BBM service was rumoured to be crawling its way onto other platforms, Apple's got in there first with iMessage, an iOS 5 messaging app that won't eat up your SMS limits, and it works over Wi-Fi and 3G.
Working on iPhone, iPod touch and iPad, you can message with one friend or multi friends - and even send photos, videos, contacts; even forward that dirty SMS you received last night from Hilda. If you start iMessaging on your iPad but suddenly have to duck out, you can resume it on your iPhone. And if your friends starts playing a game, your iMessage will pop up as a notification, and your pal can see that you're busy typing away.
RIM, it's over to you now. What can you pull out of the bag to tempt your customers to stay?
Image credit: Ars