HelpStack - Open Source mobile help framework to support iOS and Android app users.

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

Chat Center - Chat with one click, no matter what messaging app you use

Live Chat by Landbot - Live chat that combines chatbots with human chat

Helpshift - Helpshift is an in-game customer support platform that enables mobile apps to improve customer experience, drive higher ratings and increase retention.

GoSquared Live Chat - Beautiful, simple, and free live chat for your website