Avochato - Text messaging for your business.
Talkus - Chat with your website users from Slack
Message Me - Website to create your contact business card
Chatlio - When you have a business to run, your average instant messaging software just will not do. You need an internal presence upon which your entire team can collaborate on. Read more about Chatlio.
Slack with your Users - Speak to your app's users entirely within Slack
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.