ProtonMail - Secure email with absolutely no compromises. Get your free encrypted email account today.
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
GPGMail - GPGMail is an open source plugin for Apple Mail.
Windows BitLocker - This topic provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.
ElectronMail - Unofficial desktop app for ProtonMail and Tutanota end-to-end encrypted email providers
Knox - Knox offers easy disk image encryption and comes with a built-in backup service.