updated 11:54 am EST, Mon February 24, 2014
New release supports all features as other mobile implementations
The BlackBerry Messenger cross-platform communications suite will be available for Windows Phone sometime this summer. The upcoming release was noted on the official BlackBerry blog earlier today, with confirmation that the app for Windows Phone will retain the same functionality as it has on Android, BlackBerry 10, and Apple's iOS. No specific release date was noted, but the app will continue to be free.
Specifically noted as included on the Windows Phone implementation of the secure messaging standard from BlackBerry is the BBM Groups function, which allows communication with up to 50 users of the software on any platform simultaneously. Other previously-announced features, like stickers and voice, will be supported at launch as well.