Peer-to-peer file transfer and chat app for Mac and iOS, with end-to-end encryption for complete privacy and security. Underpass can communicate between your own Apple devices or with another Underpass user.

Support: For documentation and contact information, see Underpass Support.

Who: An independent software developer on Apple platforms, Jeff Johnson is the creator of Underpass and the web browser extension StopTheMadness. Jeff was a longtime engineer at Rogue Amoeba Software. Before that, Jeff worked on apps such as Knox (originally developed by MK&C, later sold to AgileBits) and the open source RSS reader Vienna.

Why: Read the story of why I wrote Underpass and why you should use it.