Slack - A messaging app for teams who see through the Earth!
Time Zone Converter - Time Zone Converter is an online productivity tool to calculate exact time across time zones.
9mCollab - Collaborate (efficiently) Conclude (fast) Contribute (in the knowledge base)
Team Time Zone - Local clocks for distributed teams who use Slack
Mattermost - Mattermost is an open source alternative to Slack.
Nomad Time - A friendly time zone converter