TeamViewer - TeamViewer lets you establish a connection to any PC or server within just a few seconds.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Splashtop Remote Support - Remotely support your clients’ computers and provide them with remote access
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
BeyondTrust Remote Support - BeyondTrust Remote Support is remote desktop access, service desk, and collaboration software for Windows, Mac, Linux, iOS (iPad, iPhone), and Android devices.
JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website