Microsoft's voice assistant, Cortana, will be available on "select" iPhone and Android devices starting on Wednesday, with Cyanogen OS suport coming later this month, according to an official blog post.
For iPhone owners, the app should be out shortly in the U.S. and China, Microsoft said. Though it can be used on its own, the app is mainly of interest to Windows 10 users, since it lets them make a command on a Windows computer or tablet and have it automatically reflected on their phone, or vice versa.
Users can, for instance, set a location-based reminder from their PC and see it triggered when they arrive somewhere with their iPhone. Similarly, packages, flights, and other data tracked through the desktop version of Cortana are pushed to iOS.
More generally the app offers the same searches and suggestions as in Windows, relying on optional data saved to Cortana's Notebook, like interests and local weather settings.
The iOS edition is more limited than its counterparts in some respects. Users can't say "Hey Cortana" to trigger the app for instance, and it can't be used to change settings or launch other apps, as with Windows devices. In terms of the new platforms, only Android users can get missed call alerts and SMS replies in Windows 10.
Likewise only Cyanogen OS, found on OnePlus phones, will get the same sort of deep integration enjoyed by Microsoft products, including settings controls and the ability to use "Hey Cortana" at any time. Owners will even be able to shut off their phone via voice.
The iPhone app will be a free download and require iOS 8 or later.