Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Pipedrive - Sales pipeline software that gets you organized. Helps you focus on the right deals, so easy to use that salespeople just love it. Great for small teams.
JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website
Zoho CRM - Omnichannel CRM for Businesses of all sizes
tawk.to - tawk.to is a free live chat app that lets you monitor and chat with visitors on your website or from a free customizable page
Freshsales CRM - A full-fledged CRM for high-velocity sales teams.