Qminder - Qminder works the way it sounds: It helps a company mind its queues.
Leadfeeder - Leadfeeder converts your website visitors into sales. Connect your website's Google Analytics to Leadfeeder and unlock the power of seeing who`s visiting your site!
slashQ - Queue management system
Clearbit - Clearbit provides Business Intelligence APIs
Zeplo.io - Message queue as service.
Lead Forensics - B2B website analytics and lead generation.