It's one of the big selling points of the BlackBerry platform, so it's hard to believe that RIM will soon be offering BlackBerry Messenger on rival platforms. However, that seems to be the case.BGR, quoting 'multiple trusted sources', claims Research In Motion is planning to bring BlackBerry Messenger, as an app to Android, and eventually to iOS as well. Details are still scarce, especially in terms of timing and price, but the site believes the company might make the software free to all users. Not for certain though, there might be a one-time fee or subscription to use it on third-party platforms.Why is it doing this? The idea is probably to take back control of its application. Other applications are mimicing the BBM experience, (like WhatsApp and Kik for example), so RIM wants to push them out of the picture and maintain a dominant position for its messaging application.The third-party version is likely to be a stripped-down version of BBM - Android and iOS users can communicate with practically anyone who has a smartphone using BBM, but they might not be able to share photos, location, or videos for example. If you want that, you'll need a BlackBerry. Nice marketing ploy.Android is said to be launching 'some time this year' and well ahead of the iPhone, purely because it's easier to work with its open platform. We'll keep you posted.