Microsoft is bringing its Cortana digital assistant to the massive audience of iPhone users later this year.

Microsoft says it will bring its Cortana digital assistant that was originally developed for Windows Phone 8.1, and later for Windows 10, to the iPhone sometime later this year The app will be a "companion" to the Windows 10 PC version of Cortana. Here's what Microsoft has to say about Cortana, which is also coming to Android.

The 'Phone Companion' app on the PC will help you install the Cortana app from the Google Play or Apple App Store onto your phone so you'll be able to take the intelligence of Cortana with you, wherever you go. The Cortana app can do most of the things Cortana does on your PC or on a Windows phone. You can have Cortana remind you to pick up milk the next time you're at the grocery store, and then your phone will wake up and buzz with the reminder. You'll be able to track a flight using Cortana on both your phone and your PC, and get the updates on the device that you're on so you don't miss anything. Everything in Cortana's Notebook will show up across all your devices and any changes you make on one device will be reflected when you use Cortana on any of your other devices. The Cortana companion app will help you complete tasks you begin on your PC wherever you are, on your phone.

However, Microsoft admits that Cortana won't have all of the features compared to the Windows Phone version:

Some features require access to the system that aren't currently possible with iOS or Android, so things like toggling settings or opening apps won't initially be available in the Cortana companions for those platforms. Similarly, the ability to invoke Cortana hands-free by saying "Hey Cortana" requires special integration with the device's microphone, so that feature will be limited to Windows Phones and PCs.

Source: Microsoft