File this under possible bug, or perhaps something more interesting, but for those running Windows 10 build 10558, which leaked onto the internet yesterday, you may find the OS installing the Phone app from Windows 10 Mobile.

Indeed, we were tipped off about it and when checking our Store for an update Phone app build 1.9.30000.0 installed to our PC running the leaked beta OS.

So what does it do? Truth be told, not too much yet. The app can call people but simply routes itself to the new Skype Video app. You can also have favorites selected. Trying to call them any other way, of course, does nothing as the OS – to our knowledge – does not have telephony built in. However, since Windows 10 Mobile and Windows 10 for PC share so much of the source code, anything is quite possible.

Is this the lead up to being able to send text messages through your phone via your PC? Will those rumors about a Surface device that can make calls to become a reality? The crazy thing is with Windows 10 almost anything is now possible.

Alternatively, we could be just looking at a fluke with the Store. Crazier things have happened, after all.

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We'll have to just wait and see what Microsoft tells us, hopefully, this Tuesday.

Thanks, Justin F., for the tip!