How does Viber celebrate being acquired for a ton of money? By bringing one of its most popular features, Viber Out, to Windows Phone 8 -- that's how. In second thought, we're probably way off. Still, the Skype rival has indeed updated its WP8 application, celebration or not, allowing users to now make calls to any phone number thanks to Viber Out. This new version also lets you send video messages and multiple photos at a time, while added Bluetooth support should make it easier for you to enjoy some hands-free action. As usual, you can grab the update from the Windows Phone Store -- and feel free to share your Viber 4.1 impressions with us in the comments below.