Calls on Slack - Make voice calls in Slack
Yodel - Group photo and video sharing. Create stories with friends, join stories from around the world.
Aircall Now - Make voice calls inside Intercom Messenger 📞💬
LivnList - Get together with your friends with video messages
Skype for Slack - Move your slack discussions to a group skype call
Lookback - See how people really use your app