Microsoft has announced new Skype apps for Windows Phone 8.1 and Windows 8.1.

At its Build developer conference, Microsoft notably revealed that the Windows Phone 8.1 dialer will include a Skype button. This button will let you auto-switch your phone call to a data-based Skype video call. You'll only be able to call people in your contacts list, and you'll need their Skype username.

"For the first time on mobile, you can easily upgrade your regular phone calls to Skype video calls," explained the Washington-based company in a blog post. "You can preview the feature in the current Store app, with more to come in the next few months."

Speaking of integration, Cortana will also feature Skype integration. That means - when Microsoft's new virtual assistant for Windows Phone 8.1 is open - you'll be able to say "Skype, video call (name)". Cortana will then open Skype and proceed with launching a call. This Skype-Cortana integration will land with Windows Phone 8.1 in the coming months.

Other Skype for Windows Phone 8.1 features include real time notifications and updates on the Live Tile, integration with People hub for video calling contacts, HD 720p video calling, instant messaging, and audio calling, among other things.

And finally, Microsoft announced Skype upgrades for Windows PC users. With the upcoming Windows 8.1 update, you'll be able to pin a modern version of Skype to your taskbar: "Skype for Windows Modern is built for touch devices," explained Microsoft. "So now your built-in Skype app can be pinned to the taskbar and accessible either on your start screen or on the desktop."

The Windows 8.1 update, which is free to Windows 8 and Windows RT users, will come with the latest version of Skype. You'll be able to pin Skype to the taskbar simply by holding down or right-clicking on the Skype tile and selecting Pin to Taskbar.