Linphone - Linphone is an internet phone or Voice Over IP phone (VoIP).
Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.
MicroSIP - MicroSIP is a free portable SIP softphone for Windows based on PJSIP stack.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
We-Talk - Free online chat rooms where people chat and meet each other and chat with the stranger and learn new cultures and make friends.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.