BlackBerry Messenger (BBM) is the official instant messaging client for BlackBerry devices.
Not only can you send instant messages with BlackBerry Messenger with images, video, voice notes, but you can also use BBM to make free voice calls on your BlackBerry device. The latest version of Blackberry Messenger allows you to seamlessly switch from a BBM conversation to a BBM Voice chat.
You can share stuff with BBM such as events, the song you're listening to, and your current location on a map. The app makes for a good alternative to SMS because you don't need to pay per message. Instead, communication is made via your 3G or WiFi internet connection.
Using BlackBerry Messenger is a real joy, thanks to its well ordered user interface. It displays lists of your contacts complete with thumbnail images, and allows you to create groups to chat with different people at the same time. BlackBerry Messenger has a Group Barcode feature, which lets you join a person's group simply by scanning a QR code.
One of the few downsides to note with BlackBerry Messenger is that not all the features are available on all BlackBerry operating systems, so if you're running an older version of BlackBerry OS, you won't get access to all of BBM's tools.
BlackBerry Messenger is a powerful, easy-to-use chat client for your device, and is one of the must-have applications for BlackBerry users.