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.
Paubox - Paubox provides HIPAA compliant email encryption without the hassle of extra steps.
ChatSecure - ChatSecure is a free and open source messaging app that features OTR encryption over XMPP.
Symantec Data Loss Prevention - Fully protect your data with the comprehensive detection technologies and unified policies of Symantec's industry leading Data Loss Prevention (DLP).
Keybase Chat - End-to-end encrypted chat built into Keybase
Microsoft BitLocker - BitLocker is a full disk encryption feature included with Windows Vista and later.