HelpScout - Help Scout is a simple, straightforward way to provide excellent support
HelpNinja - Simple & Affordable help desk
Outbound Apps by Intercom - Embed apps right inside your messages
SupportYourApp - Connecting talented people with the blooming IT industry to help them grow faster by outsourcing support.
Intercom App Store - Integrate with Intercom and grow your business
TaskUs - Outsourced customer support (powers Uber & Hotel Tonight)