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

Microsoft Teams — an enterprise platform that integrates chat, meetings, notes, and attachments into a workspace. Developed by Microsoft as a competitor to the popular corporate solution Slack.