The popular instant messaging application, WhatsApp Messenger, is now available to download for free. Currently, the app – which is a personal favorite of mine – is natively compatible with the iPhone.

WhatsApp allows you to text other users of the app completely for free. It’s also available for a variety of other smart phones, meaning your BlackBerry-owning friends can get in on the action, too. As outlined in the app’s release notes:

WhatsApp messenger is a cross platform smartphone messenger currently available for iPhone, Android, BlackBerry and Nokia phones. The application utilizes push notifications to instantly get messages from friends, colleagues and family. Switch from SMS to WhatsApp to send and receive messages, pictures, audio notes, and video messages at no cost. All features are included without the need for extra in-application purchases.

I’ve been using WhatsApp Messenger for well over a year now, and it’s proved to be the perfect app. We’re not sure how long the application is going free for, so be sure to download it as soon as possible to ensure you don’t miss out.

And if you’re a fan of WhatsApp, let us know in the comments.