Viber - Free and secure calls and messages to anyone, anywhere. Keep your conversations going no matter where you are.
Dialog Messenger - handy and feature-rich enterprise multi-device messenger available for server or cloud – Slack-like, but not Slack-limited
MiVoice Business - MiVoice Business is a business communication platform that delivers voice, messaging, mobility, presence, conferencing, collaboration and applications.
Ripcord - A desktop chat client for Discord and Slack
Screenleap - Screenleap is a web app that lets users share their device's screen over the Internet. These screens can be a desktop computer monitor or a smartphone screen or anything else that can load a web browser. Read more about Screenleap.
Done Hui - No need to switch between multiple pieces of software to get through the workday. CHATS: Communicate freely. CALENDAR: Know your team's availability, plan meetings. No more conflicts. TO-DOs: Stay on top of all projects. FILES: All files, one spot.