What's great about participating in the Windows Insider Program is that you can preview new Windows 10 features before they're available to the public. While you can find or ring your phone from the web browser using Microsoft's Device Manager, Insiders can also find their phone with the help of Cortana. Not only will Cortana find your Windows Phone, but she can also hunt down an Android phone if it has Cortana installed.
Full story from the WindowsCentral blog...