"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
After Numerous Delays, BlackBerry Messenger for iOS to Launch Today [Update: Released]
Back in September, the BBM for Android and iOS apps were delayed after an unreleased version of BBM was leaked that "caused issues" with the BBM servers.
To avoid similar issues with strong demand this time around, BlackBerry is using a staggered queue system to handle the demand. Users will install the app, enter their email address to hold their spot in line, and then will receive an email when they can start using BBM.
According to BlackBerry, there are still more than 60 million BBM users worldwide exchanging more than 10 billion messages per day. Though the BBM platform remains popular, it will need to compete with several other messaging services on iOS and Android, including WhatsApp and WeChat. WhatsApp alone has more than 300 million active users, sending 27 billion messages daily.
BlackBerry Messenger offers basic text chats, multi-person group chats, voice messaging (via push-to-talk), and image sharing. Contacts can be added via BBM PIN, SMS, email, or QR code. Users are asked to set up a profile, which includes an image, nickname, and status.
Update: The app is live: BBM is available free from the App Store. [Direct Link]