Microsoft has brought the official Skype app for Windows Phone OS out of beta. This free app is now available for download (6 MB) from the Windows Phone Marketplace, enabling Windows Phone OS users to make free voice and video calls, as well as to chat with other Skype users over 3G and Wi-Fi.

According to Microsoft, the Windows Phone version of the Skype app is only available to smartphone users whose devices are powered by Windows Phone 7.5  (Mango). Users can check what version of Windows Phone OS their mobile is running, by going to “Settings” and then “About”.

A number of new features have been added to Skype for Windows Phone such as video calling in portrait mode and friend management capabilities. These include functionality such as accepting invitations, as well as blocking and unblocking contacts.

Microsoft also said that it has tested and certified various Windows Phone OS-running devices to use the Skype app, including Nokia’s Lumia 710, Lumia 800, Lumia 900, as well as HTC’s Titan and Radar smartphones.

Skype for Windows Phone is also now available in 18 languages including English, Dutch, French, German, Italian, Japanese, European Portuguese and Brazilian Portuguese, Spanish as well as Traditional Chinese. You can check the app out in the video posted below.