Viber Windows 5.9.1
Free phone calls via VoIP, chat and messages to your friends! ...VoIP from your computer First of all, you ...contacts in your address book have automatically been  ...cost (via VoIP) all your friends who use the app ...
- PROS: Free calls via VoIP to friends, Great call quality, Supports video calls, Notificatios in system tray, Contacts and messages sync between devices
- CONS: Few advanced features, App required for PC client to work