Encrypto offers fast, cross-platform encryption to help protect sensitive files before they’re sent or uploaded through the internet. It’s unobtrusive, easy to use, and best of all, absolutely free. J.R. Bookwalter

The app allows you to share using Mail, Messages, AirDrop, and more. Encrypto is also available for Windows, so you don't need a Mac to share items. Joseph Keller

This tool lives up to its promise... The best thing about Encrypto though, is that it is really easy to use and it looks exactly the same on Mac and Windows. Roger Dixon