BlackBerry hasn't yet revealed when it plans to launch BlackBerry Messenger on Android and iOS, saying only that the service will arrive on those platforms sometime this summer. We may not have to wait for an announcement from BlackBerry itself, though, as T-Mobile U.K. appears to have decided to take it upon itself to reveal the launch date for BBM on Android and iOS.
The official @TMobileUK Twitter account just sent out a message claiming that BBM will be made available to Android and iOS users on June 27. That's just three weeks from today, so it may not be long before existing BBM users see an influx of new friends and messages headed their way. It's worth noting that BlackBerry itself has yet to make any official announcements, though, so you may want to use a pencil rather than a pen when circling 6/27 on your calendar.
BlackBerry announced its plans to release BBM for Android and iOS at its BlackBerry Live conference last month. The apps are expected to feature several major BBM features at launch, including multi-user chats, video and voice messaging, BBM Groups and the ability to add contacts using PIN, email, SMS or QR codes. BlackBerry has said that BBM will be available to consumers running Android 4.0 or higher as well as iOS 6.0 or higher.