UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.

Froged - One click solution providing easy-to-use marketing, sales and support services to turn website visitors into happy customers.

Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community

Keep Your Friends Close - A free e-book about maximizing Customer Lifetime Value

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

ChatWoot - Open-source omnichannel customer engagement platform