Meet Slack - Generate instant Google Meets by using /meet from any Slack channel, group or DM. Metings open with the correct Google Account and you Slack status updates to 'On a call' automatically.
Skype for Slack - Move your slack discussions to a group skype call
Slack - A messaging app for teams who see through the Earth!
Calls on Slack - Make voice calls in Slack
Pingly - Your communication hub — Email, text & voice in one app
Daily.co for Intercom - Free video calls & screen shares embedded in Intercom