Timezone.io - Keep track where and when your team is.
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.
Team Time Zone - Local clocks for distributed teams who use Slack
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Spacetime - Work hour and time zone management for distributed teams.
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.