PC Magazine notes porting of Windows 10 Cortana application to Apple iOS operating system as noted below

http://www.pcmag.com/article2/0,2817,2495757,00.asp

http://warenotice.weebly.com/news/cortana-for-ios-beta-now-rolling-out-to-first-waves-of-users

Microsoft has officially started its beta test of a new Cortana app for iOS. And if you’re one of the lucky few to be involved in it, consider yourself part of a fairly exclusive club. According to a blog post over at WareNotice, Apple limits TestFlight-based betas to roughly 2,000 or so people per application, and we figure there are a probably a lot more Microsoft fans looking to play around with the Cortana app than that.

If you’re in the beta, you should have received an email earlier this week to give you the good news. If you have now scoured your inbox and come up with nothing, don’t fret just yet: It’s possible that Microsoft is rolling out invites in waves, and perhaps your time will come soon.

“Your life is not limited to one device, and neither is your digital assistant. Cortana is with you on your Windows 10 PC, tablet, and phone—helping you whenever and wherever you need it. But we also know that there’s a choice of mobile devices out there, so we want help from our Windows Insiders to make sure she’s a great personal assistant on iOS too,” read Microsoft’s description in an early-November blog post.