Cortana is Master Chief’s AI guide—and friend—in Halo, but she’s also a companion app for Windows 10 PCs and Windows phones. Now she’s coming to Android and iOS devices as well. Dubbed a “personal digital assistant” by Microsoft, Cortana is capable of a wide range of helpful actions—performing internet searches, setting reminders, dictating emails, tracking flights, etc.
The Cortana app for Android and iOS will sync across platforms, so anything added to her Notebook on, say, an Android phone, will update on your Windows 10 PC as well. There are some actions she won’t be able to perform on Android and iOS that are possible on Windows phones, however—at least initially. These include toggling settings and using voice activation to start Cortana up.
Cortana is voiced by Jen Taylor, who also voiced the original character from the Halo series.