BlackBerry Messenger will be available for download on the iPhone and Android smartphones later this summer. According to a BlackBerry executive, however, the popular messaging service could soon be preloaded on rival devices. BlackBerry chief operating officer Kristian Tear revealed in an interview with CNET that the company is in talks with a number of rival handset manufacturers to include the service right out of the box. The executive noted that there is a certain level of interest from other manufacturers, however no specific partners were revealed. There are currently 61 million BlackBerry Messenger users around the world, Tear said, with some 70% using BBM daily. BlackBerry still has a long and difficult road ahead, though, since rival services like cross-platform favorite WhatsApp have accumulated more than 200 million users.