Clerk - Clerk.io, the artificial intelligence for e-commerce that knows your customers interests.
Spike.sh - Spike is an incident management platform that alerts via slack, phone and email and automatic escalations to help teams fix infrastructure problems.
MailClark - The Slack bot for external communications
Sendblue - Programmatically send iMessage and SMS
Clerk Chat - SMS for Slack
Slack Message Buttons - Making messages more interactive with buttons