Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...

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

Talkatone - Android App on. Google Play. Stop paying for cell minutes, texts & landlines; Turn your iPad or iPod touch into a phone; Call/Text even in areas with bad cell coverage; Call/Text when travelling without paying for expensive international minutes.

JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website

TextMe - TextMe is a free calls and messaging application at both local and international levels.