Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
accessiBe - Making websites accessible to people with disabilities
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
tota11y - An accessibility visualization toolkit from Khan Academy
JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website
Page Speaker - Modern web accessibility tools for agencies & webmasters