Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Zoho Meeting - Free video conferencing, online meeting, desktop sharing solution from Zoho.
JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website
Airtime - Hang out with group video, share music & videos
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
Voxox CloudPhone - Get a local or toll-free business number that automatically answers, routes and transfers calls, plus other professional business phone services.