Viber lets you send free messages and make free calls to other Viber users on any device, network, in any country!

Viber syncs with your mobile contact list and automatically detects which of your contacts are on Viber.

• messages: text, photos and stickers
• group chats
• HD voice calls
• video calls
• full synchronization between mobile and PC clients
• moving incoming calls between devices

Zoom is a program for organizing video conferencing. It provides a video telephony service that allows you to connect up to 100 devices simultaneously for free, with a 40-minute limit for free accounts.