Viber this week launched their app for Windows 8 (Windows RT) devices. The app support all the core features of this platform including: Pin, Snap, Live Tiles, Toast Notifications and others.
Best-quality HD voice calls
Text, photo and sticker messages
Receive videos and attach locations
Seamlessly transfer calls between Viber for Windows 8 and your mobile device
Pin Viber and/or specific conversations directly to the Start screen
Snap Viber to the side of your screen and work, play or browse the web with Snap View