Element.io - Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.

Vtenext - Vtenext is a platform that allows you to tackle CRM processes and customers with great ease.

ChatSecure - ChatSecure is a free and open source messaging app that features OTR encryption over XMPP.

ZEKI CRM - ZEKI CRM is a full-fledged and multi-features solution that enables businesses to fulfill all their needs in a single place.

Otr.to - A secure peer-to-peer chat in your web browser.

Teamgate CRM - Powerful CRM without the Salesforce Price tag.