Here's Microsoft's Band wearable - a fitness tracker with Cortana integration
The existence of the Band is pretty much confirmed by Microsoft itself, as the company today posted three apps via Apple’s App Store, Google’s Play Store, and its own Windows Phone Store - all being companion apps for the new wearable device. The iOS app is called Microsoft Band Sync, while the Android and Windows Phone ones are dubbed Microsoft Health.
It looks like the Microsoft Band will be able to provide "24-hour heart rate monitoring and automatic activity counting," while being integrated with Cortana on Windows Phone.
At the moment, we don’t know when Microsoft will launch its Band, and neither for what price, but we assume an official announcement is just around the corner.
sources: Windows Phone Store, Google Play, Apple App Store via Windows Central, The Verge