Blackberry Messenger (BBM) app was released this week and there were over 10 million downloads in the first 24 hours. They are hoping to be one of the leading private social networks for people who need immediate communication and IM with privacy. You have the ability to share videos, images, and text in real time. You can also chat with groups as large as 30 people at once. That is definitely a nice feature. Other competitive apps would be WhatsApp which claim to have 350 million active users and also Kik Messenger with 80 million.